Section 8 Flashcards
A patient complains of having a unilateral, persistent, stabbing pain in the neck the radiates over the back of the skull. Upon physical examination, she has hypoesthesia and tenderness in the affected area. Which of the following best describes the cervical spinal segment originates of the nerve involved in the patient’s condition?
- C2 and C3
- The greater occipital nerve, which innervates the skin of the back of the scalp up to the vertex of the skull and the ear, branches from the C2 spinal nerve.
- The lesser occipital nerve arises from the ventral rami of the C2 and C3 spinal nerves.
- The lesser occipital nerve is a sensory nerve and courses behind the sternocleidomastoid muscle.
- Damage to the lesser occipital nerve may result in occipital neuralgia.
A 28-year-old male is brought to the hospital after a motor vehicle collision. He was riding a motorcycle without a helmet and was hit in the frontoparietal region. On examination, he has a Battle sign and haemotympanum. He is also noted to have right-sided facial nerve palsy and sensorineural hearing loss. CT scan reveals a temporal bone fracture. He is appropriately treated and discharged the next day. Two days later, he returned to the clinic and was noted to have horizontal nystagmus with the fast phase to the left side. What is the most likely underlying pathology for this finding?
- Right-sided perilymphatic fistula secondary to a transverse fracture
- Perilymphatic fistula is a known complication of transverse temporal fractures.
- The nystagmus has its fast phase away from the side of the lesion.
- Facial nerve palsy occurs in approximately 20% of longitudinal fractures compared to 50% of transverse temporal bone fractures.
- Cerebellar lesions are also known to cause nystagmus; however, this is a less likely cause in this patient because of the mechanism of injury and the direction (horizontal) of the nystagmus.
A 37-year-old man presents with right arm pain and weakness in the right shoulder and hand for one week. On examination, the patient is unable to abduct the right shoulder and is unable to make a pincer grasp (‘OK’ sign) with his right index finger and thumb. The clinician orders a nerve conduction study and electromyography (NCS/EMG) to evaluate for brachial plexopathy. Which of the following findings are likely to be seen if the study is performed on the same day?
- Fibrillation potentials in the flexor pollicis longus muscle.
- Greater than 50% reduction of the compound muscle action potential of the abductor pollicis brevis at the forearm stimulation site, as compared to the wrist stimulation site of the median nerve.
- Normal study except for possible reduced motor unit recruitment in the flexor pollicis longus and flexor digitorum indicis muscles.
- Positive sharp waves, fibrillation potentials, increased motor unit action potential amplitude and duration in the flexor pollicis longus and flexor digitorum indicis muscles.
3. Normal study except for possible reduced motor unit recruitment in the flexor pollicis longus and flexor digitorum indicis muscles.
- In this case, the anterior interosseus nerve is affected as the patient is unable to make a pincer grasp with the thumb and index finger (‘OK’ sign).
- Brachial plexopathy usually leads to axonal changes (although some demyelinating features may be present). However, it has only been one week since the onset of symptoms. Thus, axonal changes will not manifest on the EMG as it takes about 3 weeks for axonal changes to manifest. Demyelinating changes, on the other hand, may manifest earlier and are usually seen as reduced recruitment of motor units.
- It is not easy to differentiate early axonal injury from demyelinating changes unless one waits for about 3 weeks to perform an EMG. At that time, due to Wallerian degeneration, early denervation changes (axonal injury) can be seen on EMG. These manifest as positive sharp waves and fibrillation potentials. In chronic axonal neuropathies, chronic denervation and reinnervation changes can be seen which manifest as reduced motor unit recruitment, increased motor unit action potential, and amplitude.
- Thus, option 1 would have been correct if the EMG was performed about 3 weeks after the onset of symptoms. Option 4 would be correct if the EMG was performed a few months after the onset of symptoms. Option 2 indicates a demyelinating lesion in the median nerve between the forearm and wrist segment. This would not be expected in a brachial plexus injury.
A 16-year-old female suffers a significant head injury after falling off a trampoline. Her past medical history is significant for type 1 diabetes mellitus and asthma. She initially has post-concussive symptoms in the hospital. Three days into her hospital stay, she starts feeling very lethargic and begins to look dehydrated. On examination, her blood pressure is 110/60 mmHg, her pulse is 89/min regular, and she has signs of dehydration. Her labs suggest serum sodium of 127 mEq/L and urinary sodium of 54 mEq/L. What should be the treatment plan for her underlying disorder?
- Restriction of salt and fluids
- Intravascular saline with increased oral intake of salt
- Salt tablets and added salt in diet alone
- Demeclocycline
2. Intravascular saline with increased oral intake of salt
- This is a case of cerebral salt wasting that presents with hyponatremia (serum sodium less than 135 meq/L) and usually increased urine sodium (urine sodium more than 40 meq/L).
- In cerebral salt wasting urine osmolality is typically elevated (more than 100 mosmol/kg).
- Syndrome of inappropriate secretion of antidiuretic hormone (SIADH) will have a similar laboratory picture as cerebral salt wasting with hyponatremia and increased urine sodium. However, with SIADH, the patient is euvolemic to hypervolemic from the retained free water as compared to the hypovolemic picture of cerebral salt wasting.
- Other causes for hyponatremia should be excluded including polydipsia, renal disease, use of diuretics, heart failure, hypothyroidism, heart failure, malignancies, hormone deficiency, and pseudohyponatremia.
A 65-year-old-female with a history of hypertension presents to the clinic complaining about back pain getting worse for six months. Pain is constant, 10/10, burning, tightening sensation, radiating from tailbone area to buttock then to left leg, worsened by sitting, bending, walking, alleviated by stretching, ice/heat pad. Pain is also accompanied by numbness/weakness on the left foot. On detailed history, she went through 3 major spinal surgeries for severe scoliosis. The first surgery that was done five years ago lasted 10 hours, involved instrumented fusion from T12 to the pelvis. Subsequent surgery was done four years ago due to hardware failure, and the last one was done one year ago to remove loose iliac bolts. Her physical exam shows a positive straight leg test on the left side and decreased sensation on the dorsal of the left foot. The laboratory tests show normal basic metabolic panel (BMP) and complete blood count (CBC). She was told no more surgeries are needed to solve the issue and feel disappointed. She comes for a second opinion regarding her treatment plan. Which of the following will be preferred advice to give?
1. Surgery
2. Steroid epidural injection
3. Pain management and psychotherapy
4. Immunoglobulin
3. Pain management and psychotherapy
- Arachnoiditis is a persistent inflammation of the arachnoid mater as well as subarachnoid space due to many possible causes such as prior spinal surgery, infection.
- It is an incurable condition that is difficult to treat. Treatment mainly focuses on alleviating pain, improving quality of life, managing symptoms, helping patients cope with the difficulties it presents.
- Pain management ranges from traditional treatment modalities like medication, physical therapy, cognitive, behavior psychotherapy, to modern treatment techniques such as thecaloscopy and neurostimulation.
- Long-term prognosis after surgery remains poor with immediate improvement followed by relapse and progressively worsening occurs later.
A 36-year-old female comes to your primary care office for daily headaches. The headaches are pulsatile, unilateral, and associated with photophobia and nausea, but without aura. The problems occur daily and significantly interfere with her quality of life. She has been experiencing these symptoms over the last 18 months. On exam, she is neurologically intact with a reasonable range of motion of her neck. She has tried multiple medications without any relief, including preventative and abortive therapy. She has gone to cognitive behavioral therapy for her headaches and recently underwent a botulinum injection, but it provided minimal relief. The clinician is considering a procedure to relieve her pain. What is the most common location of the pain, targeted for this procedure?
- Left supraorbital and supratrochlear nerves
- Bilateral greater and lesser occipital nerves
- Right greater and lesser occipital nerves
- Bilateral supraorbital and supratrochlear nerves
2. Bilateral greater and lesser occipital nerves
- This patient has chronic daily migraine headaches, given the refractory nature of her pain and failure to conservative management. The patient would be a candidate for a pericranial radiofrequency ablative nerve block. The most common location to target is the bilaterally greater and lesser occipital nerves.
- According to a 2016 study, 35% percent of pericranial ablative nerve blocks for chronic headaches target the greater and lesser occipital nerves.
- For probe placement, the greater occipital nerve is slightly inferior to the superior nuchal line and medial to the occipital artery. Lesser occipital nerve is lateral to the occipital artery and medial to the mastoid process.
- The lesser occipital nerve is located lateral to the occipital artery and medial to the mastoid process. Separately the bilateral supraorbital and supratrochlear nerves are targeted in about 14 percent of cases of pericranial nerve blocks.
A 30-year-old male patient presents to the hospital following a wakeboarding injury with an acute type II odontoid fracture in good alignment. The CT spine revealed a posteriorly oblique fracture type with a fracture gap of 2.5 mm and an angulation of 12 degrees. Magnetic resonance imaging scan (MRI) images revealed an intact transverse ligament. His body mass index (BMI) is 20 kg/m2. Which of the following is the most rational management strategy for patients presenting with such clinical characteristics?
- Halo fixation
- Rigid cervical collar
- C1-C2 posterior instrumentation
- Odontoid screw
4. Odontoid screw
- The patient has sustained an unstable type II posterior oblique odontoid fracture.
- The patient has an intact transverse ligament allowing for odontoid screw placement.
- The anterior odontoid screw fixation preserves the C1-C2 movements and is therefore preferred compared to the posterior fixation.
- The patient is otherwise thin without anatomical barriers to the technical placement of the odontoid screw.
A 58-year-old man is brought to the emergency department after having a 4-foot fall from a hammock. On physical examination, there is mild low back pain and no neurologic deficit. On computed tomographic imaging, there is an L1 fracture in the posterior vertebral body with a 25% height reduction with a widened interpedicular distance. Magnetic resonance imaging shows that the posterior ligamentous complex is intact. Which of the following is the most appropriate management strategy for this patient?
- Decompression and fusion
- Vertebroplasty
- Adequate pain control and early ambulation
- Fusion without decompression at 2 levels above and below the injured level
3. Adequate pain control and early ambulation
- In patients with an intact posterior ligamentous complex and no neurological symptoms, nonoperative treatment is recommended.
- Patients with adequate pain control can begin early mobilization without bracing.
- The use of bracing with a spinal orthosis can provide symptomatic pain relief but does not affect the outcome.
- Vertebroplasty is indicated for patients with intractable back pain after 4-6 weeks of conservative treatment.
A 24-year-old female who had delivered a healthy male baby through normal vaginal delivery one week back presents to the emergency department with severe headache and vomiting. She is not having any comorbidities and is not on any drugs other than folate supplementation. On clinical examination, her Glasgow coma scale score is 15, and she does not have any neurological deficits. Computed tomogram of the brain does not reveal any abnormalities. Neurology consultation is done, and a magnetic resonance imaging of the brain with magnetic resonance venogram is ordered. The report comes as thrombosis involving the superior sagittal sinus and right transverse sinus. The brain parenchyma is reported to be normal. Blood investigations do not show any evidence of thrombophilia. How should the patient be managed?
- Start on warfarin with target INR 2-3 and continue for 1 year
- Start on body-weighted subcutaneous low-molecular-weight heparin followed by warfarin for 3 months
- Local intravenous thrombolysis
- Mechanical thrombectomy
2. Start on body-weighted subcutaneous low-molecular-weight heparin followed by warfarin for 3 months
- The treatment of a patient with cortical venous sinus thrombosis (CVST) in the acute phase consists of either body weight- adjusted subcutaneous low-molecular-weight heparin (LMWH) or dose-adjusted intravenous heparin, provided there is no contraindication for anticoagulation.
- If CVST is due to a transient risk factor, oral anticoagulation may be given for 3 months. In idiopathic CVST and in patients with mild thrombophilia (heterozygous factor V Leiden or prothrombin G20210A mutation, and high plasma levels of factor VIII) oral anticoagulation is continued for 6–12 months. In this patient, the risk factor is transient (post-puerperal). Hence anticoagulation may be given for three months only.
- Life long anticoagulation should be given in patients with (1) recurrent CVST, (2) CVST with severe thrombophilia including antithrombin, protein C or protein S deficiency, homozygous factor V Leiden or prothrombin G20210A mutation, and antiphospholipid antibodies.
- Systemic or local thrombolysis and mechanical thrombectomy are not indicated in patients with CVST. These are tried if there is medical deterioration due to CVST, provided other causes are ruled out.
A 44-year-old male patient is being seen in the emergency department (ED) with complaints of a left eyelid drooping for two days. In the ED, his vitals were found to be stable. He underwent basic workup with CBC, metabolic profile, and chest radiograph, all of which came to be normal. The emergency team was concerned about his symptoms, so a CT head was ordered, which was normal as well. Based on these findings, neuro was consulted, and the patient was found to have left periorbital pain and restriction of the eye movements. MRI of the brain reveals contrast enhancement with thickening in the cavernous sinus region. While going over the results and the diagnosis, the patient asks about the prognosis of his condition. What should be the response?
- It is an end-stage disease and there is no treatment
- There is no recurrence of this condition
- Relapses tend to occur in about 40% to 50% of patients
- Symptoms will not get better and he will have a permanent deficit
3. Relapses tend to occur in about 40% to 50% of patients
- The patient has symptoms of Tolosa-Hunt Syndrome (THS) that is described as severe and unilateral periorbital headache associated with painful and restricted eye movements. Relapses tend to occur in about 40% to 50% of patients and can be ipsilateral, contralateral, or bilateral.
- Tolosa Hunt Syndrome is characterized by the dramatic symptomatic improvement seen with Glucocorticoids. Symptom improvement, especially pain relief, is usually seen 24 to 72 hours after starting steroids, with the majority of patients reporting improvement within one week. Cranial nerve palsies improve gradually and can take anywhere from two to eight weeks for recovery. It is unusual to have residual deficits after steroid treatment.
- Relapses are more common in younger patients than in older patients. Every relapse should ideally be investigated with a full workup as Tolosa Hunt syndrome is a diagnosis of exclusion.
- Tolosa Hunt Syndrome is characterized by the dramatic symptomatic improvement seen with glucocorticoids. Symptom improvement, especially pain relief, is usually seen 24 to 72 hours after starting steroids, with the majority of patients reporting improvement within one week. Cranial nerve palsies improve gradually and can take anywhere from two to eight weeks for recovery. It is unusual to have residual deficits after steroid treatment.
A 35-year-old who is pregnant with no previous screening is evaluated with antenatal ultrasound. The ultrasound reveals a frontal bone indentation and cerebellum wrapping around the brain stem. If an MRI is completed at a later date, which of the following would be the most likely finding?
1. Agenesis of the corpus callosum
2. Lissencephaly
3. Large posterior fossa
4. Small posterior fossa
4. Small posterior fossa
- This fetus has a Chiari II malformation. Neuroimaging with magnetic resonance imaging (MRI) is the most important modality to evaluate these patients.
- MRI posterior fossa classic findings include a small posterior fossa, brainstem appearing downwardly displaced, low-lying and elongated fourth ventricles, beaked tectal plate, and inferior displaced cerebellar tonsil and vermis through the foramen magnum.
- MRI spine fossa classic findings include spina bifida aperta, myelomeningocele, and tethered core.
- Antenatal ultrasound classic findings include the lemon sign (frontal bone indentation depicting a lemon) and banana cerebellum sign (cerebellum wrapping around the brain stem).
A 5-year-old boy presented with defective vision and with a deviated RE. The parents noticed the defective vision one year ago. On examination, vision in RE was 6/60 and LE-6/6. RE had esotropia. RE anterior segment examination was within the normal limit. RE fundus examination revealed a funnel-shaped optic nerve head. It had a central whitish fibrous tissue and was surrounded by a ring-shaped area of chorioretinal pigmentary disturbance. The retinal vessels originated as multiple straight narrow branches at the edge of the disk. Systemic association was suspected, and an MRI brain was ordered. What findings are expected on the MRI brain?
1. Herniation of brain tissue and overlying meninges through a defect in the cranium
2. Deep white matter lesions near the ventricles
3. An intracranial space-occupying lesion with obstructive lateral ventricle hydrocephalus
4. A dural-based mass which is isointense on T1 and T2 and enhances vividly
1. Herniation of brain tissue and overlying meninges through a defect in the cranium
- RE fundus evaluation reveals features of morning glory syndrome (MGS). It is a primary mesenchymal abnormality with a partial development of the lamina cribrosa and incomplete closure of the posterior sclera wall. It is characterized by a funnel-shaped optic nerve head. It has a central whitish fibrous tissue and is surrounded by a ring-shaped area of chorioretinal pigmentary disturbance. The retinal vessels originate as multiple straight narrow branches at the edge of the disk. MGS can be associated with basal encephalocele.
- Basal encephalocele is the herniation of neural tissue through a defect in the basal skull. MGS is usually associated with the trans-sphenoidal type. Other reported basal encephaloceles include spheno-ethmoidal, sphenopharyngeal, and trans- ethmoidal. These defects can be misdiagnosed as nasal polyps; it is thus important not to biopsy such lesions.
- MRI is the modality of choice for a case of encephalocele. It helps to delineate the location of the encephalocele, characterize the hernia sac (based on the size, contents, and status of the herniated neuroparenchyma), and identify other associated intracranial malformation. All the above factors help in preoperative planning and prognosis.
- The child has MGS. MGS can be associated with basal encephalocele. On MRI, it is identified by herniation of brain tissue and overlying meninges through a defect in the cranium. MRI deep white matter lesions near the ventricles are seen in multiple sclerosis. An intracranial space-occupying lesion with obstructive lateral ventricle hydrocephalus can be seen in tuberculoma or neoplasm. A dural-based mass that is isointense on T1 and T2 and enhances vividly suggests meningioma. Thus herniation of brain tissue and overlying meninges through a defect in the cranium is correct.
A 45-year-old man is admitted to the hospital and managed supportively following a severe head injury. The neurological examination revealed brainstem areflexia. The apnea test did not elicit any spontaneous respiratory drive in the patient despite the arterial blood PCO2 level of 60 mm Hg. However, on painful stimulus, the patient occasionally shows flexion and crossing of his arms over his chest. What is the next step in the management of this patient?
- Declare brain death
- Continue supportive management
- The patient is in a persistent vegetative state
- Do ancillary tests for diagnosing brain death
1. Declare brain death
- The patient with brain stem death can sometimes show limb movements secondary to spinal reflexes. This is still is compatible with the diagnosis of brain death.
- The characteristic movement shown by the patient is typical of Lazarus sign sometimes seen in brain death patients.
- Coma, brain stem areflexia, and a positive apnea test is confirmatory of a brain death status.
- The ancillary tests are only justified in cases wherein the apnea test is inconclusive, hazardous, or in patients in whom brainstem reflexes should not be elicited such as vestibulo-ocular reflex in patients with cervical cord injury.
A 16-year-old patient was being managed with tracheostomy following a severe head injury. The patient was later decannulated following his neurological improvements. However, the patient kept having stridor with tachypnea uniquely when placed in the supine position. There was some improvement when the patient was nursed in the lateral position. What might be the probable cause for such findings in the patients?
- Subglottic stenosis
- Tracheoesophageal fistula
- Vocal cord paralysis
- Tracheomalacia
4. Tracheomalacia
- The symptoms of respiratory stridor in patients, especially in a supine position, are characteristic following removal of the tracheostomy tube is characteristic of tracheomalacia.
- Tracheomalacia results from an ischaemic injury to the tracheal cartilages with subsequent destruction and necrosis. This leads to a gravity-mediated collapse of the weakened trachea, especially in a supine position.
- Making a high incision in the trachea while creating a stoma leads to damage to tracheal cartilages in the first and second tracheal rings, thereby predisposing to tracheomalacia.
- Stridor due to subglottic stenosis will not improve upon the lateral or prone positioning of the patient. Tracheoesophageal fistula presents with choking and coughing right after each feeding of the patient.
52-year-old female presents with cognitive issues. She claims that she has difficulty finding words and forgets the names of familiar people. She would frequently lose small objects like her wallet and keys and would have to search for them as she cannot recall where she placed them. She is still able to do daily activities without issues and still handles her finances. Her mother had a stroke at 56-years-old, and her older brother has dementia. She has a history of migraine with aura for the past 20 years, mild stroke 5 years ago with no deficits, no hypertension or diabetes. She does not smoke or take alcohol. Mini-mental status exam is 24, no motor and sensory deficits, (+) Babinski bilaterally. A cranial MRI was requested. Which of the following would you expect to see?
1. T2/Fluid-attenuated inversion recovery (FLAIR) hyperintensities on the corpus callosum and optic nerve lesions
2. T2/FLAIR hyperintensities in the occipital lobe
3. T2/FLAIR hyperintensities in the anterior temporal pole
4. Atrophy of the frontal and temporal lobe
3. T2/FLAIR hyperintensities in the anterior temporal pole
- Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) should be suspected in patients with a strong family history of early strokes and dementia. The most common symptoms are migraine headaches, cognitive deficits, ischemic episodes, and psychiatric disorders. The average age of onset is around 30 years. A migraine with aura is the most common initial symptom, present in about 55% of people diagnosed with CADASIL, and slightly more common in women.
- CADASIL has a somewhat characteristic appearance on MRI, and a radiologist may suggest the diagnosis. Abnormal T2/FLAIR white matter hyperintensities, similar in appearance to those seen with the chronic microvascular disease, are present in CADASIL in the anterior temporal, external capsule, and paramedian superior frontal subcortical white matter. Microbleeds are seen with a greater prevalence in CADASIL patients. These are best seen on a T2*- gradient recalled echo (GRE) MRI sequence as multiple punctate foci of susceptibility/hypointensity.
- The lesions in the anterior temporal pole distinguish CADASIL from ischemic leukoaraiosis.
- Optic nerve and corpus callosum lesions are more commonly found in multiple sclerosis.
A 16-year-old male patient was brought to the emergency department after a motor vehicular accident. On examination, vital signs reveal blood pressure 140/85 mmHg, heart rate 112 bpm, the regular, temperature was afebrile. He was drowsy but easily arousable, oriented, and able to follow commands. He has a 3 cm laceration on the left parietal region, and he complains of severe headache. The cranial nerve examination was normal. The motor exam shows a drift on the right upper and lower extremity with a 40% sensory deficit on the right. Babinski was positive on the right. A head CT was requested, which shows a crescent-shaped hyperdensity on the left cerebral convexity with mass effect and midline shift of structures. Surgical intervention should be done urgently in this patient in which of the following scenario?
1. GCS 14
2. Hematoma thickness of 9mm
3. Midline shift of 7mm
4. ICP of 18mmHg
3. Midline shift of 7mm
- Surgery for decompression of subdural hematoma is done if there is a midline shift of 5 mm or greater.
- Surgery also is indicated if there is an acute subdural hematoma that exceeds 10 mm in thickness.
- Sometimes, if the midline shift is 5 mm and there are no neurological deficits like dilated pupils or elevated intracranial pressure, observation can be adequate.
- Surgery is recommended when a subdural hematoma is associated with compressed basilar cisterns.
A 3-month-old baby boy had a ventriculoperitoneal shunt placed when he was 21 days old. He was pre-term and had a grade III intraventricular hemorrhage, which was initially treated with serial anterior fontanelle taps but eventually required the shunt. On a routine visit, the mother asked the pediatrician what signs should she evaluate to confirm adequate shunt function. Which of the following represents evidence of proper function?
1. Good urine output
2. Loud crying sounds
3. Bulging fontanelle
4. Normal head circumference
4. Normal head circumference
- Shunt malfunction will accumulate cerebrospinal fluid, which may lead to an increased in head circumference.
- Shunt dysfunction in toddlers and infants presents with enlargement of the head, full tense fontanel when the baby is upright, prominent scalp veins, swelling along shunt tract, vomiting, irritability, sleepiness, downward deviation of eyes, less interest in feeding, loss of previous milestones.
- Children and adults with shunt malfunction present with nausea, vomiting, headache, vision problems, irritability, tiredness, swelling along shunt tract, personality change, loss of balance, difficulty waking up or staying awake, a decline in academic or job performance.
- Urine output does not have a correlation with shunt functionality as the cerebrospinal fluid is absorbed in the peritoneal cavity
A 61-year-old man is brought to the emergency department for abrupt loss of consciousness after a fall at his home that happened 2 hours ago. His past medical history is notable for atrial fibrillation and New York Heart Association class 3 congestive heart failure. He has otherwise been well without additional medical problems. His medications include warfarin and metoprolol. Currently, his temperature is 98.6, his blood pressure is 125/75 mm Hg, his pulse rate is 77/min and irregular, and his respiration rate is 17/min. The patient is obtunded without localizing neurologic findings. The cardiac examination reveals an irregularly irregular rhythm. The remainder of the examination is unremarkable. A head CT scan shows a large subdural hematoma. Lab values indicate a hemoglobin level of 12.8 g/dL, platelet count of 283,000/μL, and INR of 3.0. Intravenous vitamin K is administered, and plans are made for emergent neurosurgery. Which of the following is the next most appropriate step in managing this patient?
1. Fresh frozen plasma
2. Factor IX complex
3. Cryoprecipitate
4. Idarucizumab
2. Factor IX complex
- Factor IX complex, known as prothrombin complex concentrate (PCC), should be used to reverse the effects of warfarin anticoagulation in patients experiencing severe bleeding and those requiring urgent surgery.
- Although vitamin K alone can be effective in reversing the effect of warfarin, its hemostatic effect can take several hours.
- In urgent situations, simultaneous replacement of the vitamin K– dependent coagulation factors are necessary. Fresh frozen plasma treatment involves a large volume infusion and may cause problems in a patient with congestive heart failure.
- Cryoprecipitate would be indicated to treat severe hypofibrinogenemia, usually arising as a consequence of disseminated intravascular coagulation (DIC) or severe liver disease. Idarucizumab is a monoclonal antibody that binds the non–vitamin K antagonist oral anticoagulant dabigatran and causes a rapid reduction in available dabigatran in the body for up to 24 hours. Idarucizumab will not reverse warfarin anticoagulation.
A 65-year-old patient with a past medical history of a previous extensive laminectomy with medial facetectomy at L4 and L5 levels presents to your office with persistent, localized pain at the operative site. The patient complains of shooting back pain in his lower lumbar region that radiates into his posterior left leg. The patient states his pain is worse with prolonged walking or standing up straight and improves with bending forward. On physical exam, he is tender to palpation over the area of pain, and he has a decreased sensation in the distribution of the L4 dermatome on the left. Muscle strength is intact bilaterally for his lower extremities, but his deep tendon reflex is 1/4 for L4 on the left, and 2/4 bilaterally for S1. Straight leg raise is positive on the left. The dynamic x-ray films degenerative arthritis of the lumbar spine. What is the origin of the characteristic pain in the patient?
- Faulty hardware
- Traversing nerve root
- Nerve of Luschka
- Infective pathology
2. Traversing nerve root
- When discussing radicular pain, it is crucial to review human neuroanatomy, where nerve roots exit the spinal cord.
- Patients with symptomatic spinal stenosis will experience symptoms of neurogenic claudication due to compression of the transversing nerve root.
- Patients with neurogenic claudication often have bilateral and asymmetrical radicular pain, weakness, and or sensory loss of the lower extremities. These symptoms are made worse by walking or standing for prolonged periods. An L5 nerve root compression occurs from central disc protrusion of L2-L3 or L3- L4, a lateral disc protrusion at L4-L5, or from a far-lateral protrusion at the foramen at L5-S1.
- The involvement of the existing and the traversing nerve roots leads to radicular pain characterized, such as sciatica. The areas of the body which we can contribute to a single nerve root are called autonomous zones. These independent areas of lumbosacral radiculopathy include the anterior thigh (L2 and L3), the medial calf (L4), and the dorsum of the foot (L5), and the sole (S1).
A 30-year-old primiparous woman with a BMI of 32 kg/m2 requests epidural analgesia for labor pain. After obtaining consent, the epidural space is located at a depth of 7 cm with loss of saline resistance. A catheter is inserted successfully into the epidural space through a Tuohy needle despite initial slight resistance. On removal of the needle, it is noted that the catheter broke at the 6 cm mark, and the missing segment is not seen either on the drapes or the floor. Which of the following is the next most appropriate step in the further management of the broken epidural catheter?
- CT scan of the lumbar region
- Plain x-ray of the lumbar region
- Surgical exploration of the back for the missing segment of the catheter
- Perform an epidural at a different space
1. CT scan of the lumbar region
- The epidural catheter is radioopaque; it may be visible on plain x-ray, but a CT scan is the most helpful in delineating the broken catheter tip location.
- The catheter fragment is unlikely to cause any further problems to the patient, but fibrosis around the nerve root may produce radicular irritation signs.
- An immediate management plan for labor analgesia should be instituted. This may include a discussion with the patient and obstetrician and depends on the progress of labor.
- Epidural anesthesia is a safe procedure and is routinely performed by anesthesiologists. Breakage of an epidural catheter is rare but a worrisome complication. However, if this happens, the presence of retained epidural catheter fragment should be properly documented and informed to the surgical team and the patient.
A 65-year-old man with a history of peripheral artery disease and hypertension is brought to the clinic for evaluation. His wife reports sudden personality changes, nausea, third cranial nerve palsy, and vision loss. Which artery is most likely affected?
1. Anterior cerebral artery
2. Middle cerebral artery
3. Vertebral artery
4. Basilar artery
4. Basilar artery
- Rostral brainstem infarction (top of the basilar syndrome) is known to cause sudden behavioral changes, oculomotor deficits, and visual loss.
- Motor function is usually preserved.
- This is usually a result of atherosclerotic disease.
- Posterior circulation strokes often present with nausea.
A 38-year-old woman presents to the clinic complaining of spontaneous galactorrhea. The patient has a history notable for severe claustrophobia. The review of systems is unremarkable. Visual fields and cranial nerves are intact. Her serum prolactin level is 177 ng/mL (normal range: 2 – 29 ng/mL) and urine HCG is negative. What is the next best step in the evaluation of this patient?
1. CT sella protocol with intravenous contrast
2. CT sella protocol without intravenous contrast
3. CT angiogram of the head
4. Radionuclide cisternography
1. CT sella protocol with intravenous contrast
- A dedicated MRI protocol with and without intravenous contrast is the first-line choice for evaluating for a functional pituitary microadenoma. However, if patients have absolute contraindications to MRI (claustrophobia, a noncompatible pacemaker or metallic foreign body), a CT with intravenous contrast may be obtained.
- Noncontrast CT imaging of the pituitary adds little diagnostic value. This repeat imaging increases the patient’s radiation dose without clinical benefit. This is even more relevant to newer CT scanners, which can generate virtual noncontrast images without any added radiation dose to the patient.
- A CTA head with intravenous contrast is an ideal study to evaluate for vascular regions within the head. However, this is not a recommended imaging study for the initial evaluation of possible pituitary microadenoma.
- Radionuclide cisternography is not indicated for the evaluation of pituitary adenomas.
A 58-year-old woman with a past medical history significant for insulin-dependent type 2 diabetes, hypertension, hyperlipidemia, and morbid obesity presents to the office for further evaluation of right leg burning, tingling, and difficulty ambulating over the last two months. She denies any sharp or dull achy pain. Pain is worse with walking, states she has been having difficulty standing on her toes. Her symptoms have not been getting worse or better. She states she had similar symptoms a few years ago, but they went away on their own. She denies any bowel or bladder incontinence or saddle anesthesia. On physical exam, she is noted to have diminished sensation along the S1 dermatome of her right leg. Lower extremity muscle strength is 5/5 on the left and 3/5 on the right in leg extension. Her deep tendon reflexes are 2/4 for L4 but diminished 1/4 for S1 on the right and 2/4 on the left. The straight leg raise is negative. She has an antalgic gait upon ambulation and difficulty walking on her toes. Which of the following is the next best step in the management of this patient?
1. Electromyography
2. MRI of the lumbar spine
3. Physical therapy
4. X-ray of the foot 3 views
2. MRI of the lumbar spine
- The median duration of diabetes is four years before being diagnosed with diabetic amyotrophy. Diabetic amyotrophy is a specific type of lumbosacral plexopathy. MRI with gadolinium contrast is the best test for the evaluation of the lumbosacral plexus.
- The differential diagnosis of lumbosacral plexopathy is broad, including radiculopathy. An MRI can help differentiate plexopathy from radiculopathy.
- Conventional magnetic resonance imaging (MRI) is useful to localize the area of injury or disease and identify the likely cause of lumbosacral plexopathy.
- In diabetic or idiopathic amyotrophy, symptoms of plexopathy are likely due to either ischemic injury secondary to a microscopic vasculitis or possible demyelination secondary to axonal dystrophy. These findings could be seen on MRI.
A 62-year-old man presents with a three-day history of a new-onset frontal headache that progressed to a generalized headache. He describes the pain as a nine out of ten, throbbing, and does not improve with over the counter medications. He denies any changes in vision, vomiting, seizures, limb weakness, behavioral changes, or weight loss. He has a past medical history of hypertension, type 1 diabetes mellitus, and a 37 pack-year smoking history. However, he is not compliant with his medications. He denies any family history of a cerebral hemorrhage. His vital signs show oxygen saturation 98% on room air, respiratory rate 26 per minute, heart rate 79 bpm, blood pressure 162/96 mmHg, and temperature 98 F. The physical examination is unremarkable. A CT scan of the brain reveals an isolated hyperdense right temporal occipital lobe lesion measuring 1.7 cm in its longest axis. An MRI shows a large right temporal occipital lesion, with several smaller lesions bilaterally with surrounding edema. What is the most appropriate initial step in the management of this patient’s condition?
1. Administer intravenous dexamethasone
2. Surgical resection
3. Whole-brain radiotherapy
4. Stereotactic radiosurgery
1. Administer intravenous dexamethasone
- The first step in the management of newly diagnosed brain metastases is the treatment of intracranial edema.
- Oral or intravenous steroids, such as dexamethasone, are commonly used. A loading dose of 10 mg intravenous (IV) dexamethasone followed by 4 mg IV every six hours is one dosing regimen.
- After the initial clinical response, which can occur rapidly, the dose may be tapered to avoid many of the long-term high-dose steroid administration’s adverse effects.
- Following the initiation of steroids, definitive management may be initiated. Treatment options include surgical resection (for limited brain metastases in patients with good performance status and surgically accessible lesions), whole-brain radiotherapy, and stereotactic radiosurgery.
A 25-year-old rugby player, who sustained a head trauma two days ago, presents to the hospital with complaints of a vertical double vision, which increases with the downward gaze. On examination, the left eye is tilted upward as compared to the right eye. Which direction should the patient asked to look to test the function of the paralyzed muscle?
1. Upward only
2. Downward only
3. Down and in
4. Down and out
3. Down and in
- Looking ‘down and in’ isolates the function of the superior oblique muscle and is the proper way to test the function of this muscle.
- Injury to the trochlear nerve (CN IV) results in weakness of the downward movement of the eye.
- Trochlear nerve palsy also results in the tilting of the affected eye upward due to the unopposed action of the rest of the eye muscles.
- ‘Upward only’ movement of the eye is due to the action of the superior rectus muscle. ‘Down and out’ movement of the eye tests the action of the inferior rectus muscle. ‘Downward only’ movement of the eye is due to the action of the inferior rectus muscle.
A 48-year-old woman with a history of asthma and known ovarian tumor presents to the clinic with new back pain and bilateral lower extremity weakness. She is status-post hysterectomy with salpingo-oophorectomy and additional chemo- radiation 2 years prior to the current presentation. On examination, she has mild hip flexor weakness which is fairly symmetric bilaterally. She has preserved sensation and deep tendon reflexes. During her initial workup, hematology and metabolic labs are normal and her neuroimaging does not show any abnormality with gadolinium enhancement of the nerve roots. EMG nerve conduction studies are planned to help diagnose the underlying etiology. Which of the following sets of findings is most consistent with radiation-induced lumbosacral plexopathy in this patient?
- Nerve conduction studies: normal sensory and reduced amplitude of compound motor action potentials; needle electromyography: fibrillation and polyphasic potentials.7
- Nerve conduction studies: normal sensory and reduced amplitude of compound motor action potentials; needle electromyography; fibrillation potentials with positive sharp waves and no polyphasia
- Nerve conduction studies: absent sensory and reduced amplitude of compound motor action potentials: needle electromyography shows myokymic potentials
- Nerve conduction studies: normal sensory and motor nerve action potentials; needle electromyography: fibrillation potentials with polyphasic potentials
3. Nerve conduction studies: absent sensory and reduced amplitude of compound motor action potentials: needle electromyography shows myokymic potentials
- Myokymic potentials in conjunction with other findings of plexus involvement noted on nerve conduction studies (such as low amplitude or absent sensory and motor nerve action potentials) are pathognomonic of radiation-induced plexopathy.
- Bilateral involvement is likely more indicative of radiation- induced plexopathy as opposed to neoplastic lumbosacral plexopathy which presents unilaterally.
- The nerve conduction study and EMG have to be taken in conjunction with the clinical presentation and not independently.
- Radiation-induced plexopathy typically presents about a year or later from the time of initial radiation to the pelvis.
A 50-year-old male with a past medical history of HIV and HAART therapy presented with worsening headaches for the last 4 weeks. He underwent a CT head, which showed a left- sided mass in the frontal lobe, and an MRI confirms the mass. CSF shows atypical cells and positive for the Ebstein Barr virus. Flow cytometry shows CD 20 +ve cells. Opthalmology evaluation shows a possible retinal involvement, the biopsy of which showed a diffuse large B-cell lymphoma. What should be done next?
1. A repeat lumbar puncture for further testing
2. Radiation to the mass in the frontal lobe
3. High-dose methotrexate based therapy
4. Surgery with stereotactic radiosurgery
3. High-dose methotrexate based therapy
- Primary CNS lymphoma should be aggressively treated with high-dose methotrexate based therapy.
- Ebstein Barr virus may have a causal link for the development of primary CNS lymphoma.
- About 25% of patients with primary CNS lymphoma, has the involvement of the eye.
- Radiation or surgery is not first-line therapy for the treatment of CNS lymphoma.
A 60-year-old man is brought to the outpatient department with a complaint of severe headache for the past two hours associated with vomiting. On examination, he does not have any neurological deficits. A computed tomogram scan of the head shows hyperdensity in the left Sylvian fissure. Which of the following drugs is approved by the FDA to reduce the incidence and severity of ischemic deficits in this patient?
1. Nicardipine
2. Nisoldipine
3. Clevidipine
4. Nimodipine
4. Nimodipine
- Nimodipine is FDA approved to improve the neurological outcome in patients treated for subarachnoid hemorrhage.
- Nicardipine is FDA approved to treat chronic stable angina as an immediate-release product and management of hypertension as an immediate and sustained-release product.
- Nisoldipine is FDA approved to treat hypertension.
- Clevidipine is FDA approved to treat hypertension.
A 40-year-old man presented to the emergency department with acute, sudden onset back pain radiating down both legs. He reports some altered sensations in his genitals and has not passed urine. He has a history of chronic back pain and takes paracetamol, tramadol, and pregabalin. He tells you that he has had an MRI scan of his spine in the past, but surgical intervention was not recommended. Examination of his lower limbs reveals 4 out of 5 MRC power bilaterally and altered sensation along the L4, L5, and S1 nerve root bilaterally. There is some melted sensation in the saddle area, but the sensation remains intact. A PR exam reveals normal tone and reflex is present. A bladder scan reveals a residual volume of 100 mL. His current presentation is then superseded by an interval MRI scan of his lumbosacral spine. The scan is compared to the previous and shows that the large 5 cm multiloculated cyst arising from the L5 nerve root sheet has changed in appearance and shows changes that represent an acute hemorrhage within the cyst long. There is incomplete compression of the cauda equina. The scan is compared to the previous and shows that the large 5 cm multiloculated cyst arising from the L5 nerve root sheet has changed in appearance and represents an acute hemorrhage within the cyst wall. There is incomplete compression of the cauda equina. How would you proceed with management?
1. Reassurance and discharge
2. Admission for monitoring
3. Urgent decompression of L5
4. L5 Nerve root block for relief
- Reassurance and discharge
- Tarlov cysts are usually incidental, asymptomatic findings on an MRI scan. However, some may be causing the patient symptoms, and some may have complications such as bleeding in this case.
- There is limited evidence in the literature on the optimal management of partial cauda equina compression secondary to hemorrhage within a Tarlov cyst. However, it is noted that without significant signs and symptoms of cauda equina clinically, Conservative management may be an option.
- Bleeding is a recognized complication and may be the pathophysiology behind developing a Tarlov cyst, i.e., secondary to trauma. However, they may mimic cauda equina syndrome, admission and monitoring of symptoms would provide the least invasive option. Yates et al. have described successful management this way, with symptom-free disease at five years.
- Reassurance and discharge are incorrect due to signs and symptoms and a radiological indication of partial compression of cauda equina. Decompression surgery at this stage may be justifiable depending on severity and discussion with the patient. But the clinical signs for cauda equina compression are not as severe and may initially be amenable to conservative management. An L5 nerve root block at this stage is not advisable given an acute hemorrhage.
The orthopedic and neurosurgical teams are called to the operating room for a 34-year-old male patient who suffered an ejection from a motor vehicle rollover accident. While neuromonitoring is available and being used, the team notices a decrease in amplitude, and latency is noted with the N14 potential. What is the most likely source of these changes requiring surgical attention?
1. A brachial plexus injury sustained during prolonged labor on a macrosomic neonate
2. An unstable cervical spine in a patient extracted from an MVC
3. An elderly patient who has fallen and sustained an expanding subdural hematoma
4. Crush injury to the lower extremity in a factory worker
2. An unstable cervical spine in a patient extracted from an MVC
- Although this patient’s cervical spine status is unknown, were they to have an injury to the area it would be most likely to affect the N14 potential, which is generated at the cervicomedullary junction.
- This should be a concern while evacuating the patient from the motor vehicle. The N14 potential is generated at the cervicomedullary area.
- An expanding subdural hematoma would most likely affect the N20 potential, which is generated at the cortex.
- A lower extremity would most likely affect peripheral nerve potentials from the lower extremity, such as N8 generated from the tibial and sciatic nerves.
A 30-year-old primigravida undergoes a lower segment cesarian section under spinal anesthesia due to the non- progression of labor. Postoperatively, she has severe headaches, especially on standing up. She subsequently undergoes an epidural blood patch for the management of her problem. What is the most common problem with this treatment?
1. The requirement of several blood patches to obtain relief
2. They often require surgical exploration
3. Infection at the injection site
4. Back pain
- Back pain
- It is very uncommon to require more than two epidural blood patches (EBPs) to resolve a post-dural puncture headache (PDPH).
- Surgical exploration for persistent PDPH is rare.
- Infection at the site of EBP occurs in less than 1% of patients.
- Back pain from autologous blood injection may limit the volume of blood to be injected. Most patients will have some degree of back discomfort, usually lasting up to 2 weeks
A 10-year-old boy is under treatment for acute lymphoblastic leukemia and is planned for intrathecal methotrexate to prevent CNS relapse. Where is the most appropriate point of access to the intrathecal space in this patient?
1. Lumbar puncture
2. Right frontal
3. Right parietal
4. Ventriculoperitoneal shunt
2. Right frontal
- Ommaya reservoir, a dome-shaped port with an intraventricular catheter attached to it, is commonly used for delivery for antineoplastic drugs into the intrathecal space.
- Ommaya reservoir is routinely placed subcutaneously over the right Kocher’s point, which is approximately 2-3 cms away from the midline and 1 cm anterior to the coronal suture. Unless indicated for a tumor cyst or in the presence of anatomical distortion, the intraventricular catheter is placed through a burr hole over right Kocher’s point.
- The bulge over the scalp is palpated, and under aseptic precautions, a butterfly cannula is inserted at an oblique angle to penetrate the reservoir.
- Ommaya reservoir helps prevent repeated lumbar punctures. Unless indicated for a tumor cyst or by the presence of anatomical difficulty, the intraventricular catheter is placed through a burr hole over right Kocher’s point.
A 40-year-old male was brought by an ambulance to the emergency department after a fall and accompanying head trauma. He denies any loss of consciousness. The initial primary survey showed his blood pressure was 105/74 mmHg, heart rate was 110/min, respiratory rate was 18 breaths/min, and oxygen saturation was 96% at room air. On physical examination, the patient was noted to have periorbital ecchymosis with tarsal plate sparing and hemotympanum. There was also a left-sided complete facial weakness. What will be the most likely finding on the CT-scan of the skull?
1. Comminuted fracture of the ethmoid bone
2. Discontinuity in the left petrous temporal bone
3. Transverse fracture of the right temporal bone
4. Osseous defect in the cribriform plate
2. Discontinuity in the left petrous temporal bone
- The base of the skull includes at least five bones; the cribriform plate of the ethmoid bone, the orbital plate of the frontal bone, the petrous and squamous portions of the temporal bone, the sphenoid, and the occipital bones.
- The most common bone involved in basilar skull fractures is the petrous portion of temporal bone. A CT-scan of the skull is most likely to show a fracture of the petrous temporal bone,
- Fractures that involve the petrous ridge of the temporal bone will cause blood to pool behind the tympanic membrane causing it to appear purple, which is called hemotympanum. Periorbital ecchymosis (raccoon eyes): Pooling of blood surrounding the eyes is most commonly associated with fractures of the anterior cranial fossa.
- Temporal fractures, which are most common, are associated with carotid injury, injury to cranial nerves VII or VIII, and mastoid cerebrospinal fluid leak.
A 40-year-old man presents with severe lower back pain for the past week, which started after trying to lift a weight at the gym. The pain is radiating down the left lower limb, and he is feeling weakness in his limb. He comes with a magnetic resonance imaging scan of the lumbar spine, which reveals a far lateral disc herniation at L4-5 on the left side. What can the neurological deficit be expected in this patient in his left lower limb?
1. Difficulty in ankle dorsiflexion
2. Difficulty in ankle plantarflexion
3. Difficulty in great toe dorsiflexion
4. No weakness
1. Difficulty in ankle dorsiflexion
- Paracentral disc herniation in the lumbar region characteristically strikes the root exiting below the disc space. An L4-5 disc herniation most often compresses the traversing L5 nerve root.
- Very lateral herniated disks may compress the upper root. A far lateral L4-5 herniation can compress the L4 root (producing ankle dorsiflexion weakness).
- Free fragments can migrate and compress roots at other levels.
- MRI imaging is superior to myelography, CT, or CT myelography in the diagnosis of disc bulge, protrusion, herniation, extrusion, or migration.
A 35-year-old female presents to the outpatient department with the complaint of occasional mild to moderate frontal headaches over the past few months. She also gives a history of blurring of vision. She does not have galactorrhea or amenorrhea. She comes with a magnetic resonance imaging scan of the head, which shows a sellar lesion extending to the suprasellar location and displacing the chiasm. Which of the following is the most sensitive ophthalmologic test for detecting optic pathway compromise secondary to this tumor?
1. Peripheral visual field testing
2. Central visual field testing
3. Examination of the fundus
4. Color vision testing
1. Peripheral visual field testing
- The patient is having a pituitary macroadenoma.
- The compression of the chiasm causes visual field abnormalities in a pituitary adenoma.
- The most sensitive test for detecting optic pathway compromise due to a pituitary tumor is peripheral visual field testing.
- Decreases in color perception are much less sensitive in the diagnosis of optic nerve compression.
A one-month baby boy is rushed to an emergency department following an accidental fall injury at home. CT head revealed an indentation of 1 cm without any fracture line at the left parietal bone. There were no intracranial lesions. What is the recommended plan of management for the child?
1. Surgical elevation
2. Vacuum-assisted elevation
3. Conservative management
4. Craniotomy and mesh repair
3. Conservative management
- The presence of an indentation of the skull without any fracture line indicates a ping pong fracture.
- The skulls in newborn and young infants are elastic compared to that of the skull in the adult. This leads to a ping pong pattern of fracture.
- The elastic nature of the skull also allows for the slow remodeling of the fracture owing to the growth of the brain, especially in small-sized lesions with no other intracranial traumatic pathologies.
- Surgical management of ping pong fracture is only indicated in cases of 1) large defect, 2) when associated with other traumatic intracranial lesions, and 3) aesthetic purposes.
A 50-year-old female with a 20-year-history of intermittent intorsion of the left eye and vertical episodic double vision is referred for extraocular muscle surgery to improve the symptoms. Which operation is the best procedure for this patient?
- Left superior oblique tenotomy and ipsilateral recession of the inferior oblique muscle
- Left superior oblique tenectomy with contralateral inferior rectus recession
- Left inferior rectus recession and left inferior oblique recession
- Left trochlectomy with right inferior rectus recession
- Left superior oblique tenotomy and ipsilateral recession of the inferior oblique muscle
- The cause of the symptoms in this patient is the repeated overaction of the left superior oblique muscle causing left superior oblique myokymia.
- Surgery to weaken the superior oblique muscle alone will increase double vision because of the overaction of the inferior oblique muscle.
- Weakening of the left superior oblique muscle combined with the weakening of the ipsilateral inferior oblique muscle with recession will give the best result in this patient.
- The contralateral inferior rectus (the right inferior rectus muscle in this case) sometimes needs to be recessed in addition to the ipsilateral surgery if there is persistent double vision.
A 38-year-old woman in her first pregnancy delivers a 4800-gm baby boy. When she attempts to walk, she scuffs the toes of her right foot. She elevates her right foot higher than normal to avoid scuffing her toes (steppage gait). Neurological examination reveals a weakness in the muscles of the anterior crural compartment. Sensory losses are present in the lateral leg and dorsum of the foot. Damage to which of the following could account for the patient’s condition?
- Deep fibular nerve
- Lumbosacral trunk
- Superficial fibular nerve
- Tibial nerve
2. Lumbosacral trunk
- The patient has suffered a foot drop in her right foot.
- The patient’s first pregnancy and very large baby boy are risk factors for neurological damage during parturition.
- The patient’s sensory losses are consistent either with a lesion of the lumbosacral trunk (L5) or the superficial fibular nerve.
- The deep fibular nerve could account for the foot drop, but the only sensory innervation by this nerve is the area between the big and second toes. The tibial nerve has no role in the development of foot drop.
A 62-year-old man presents to the clinic after sustaining an injury in a motor vehicle accident. He is having difficulty heel-walking and has diminished sensation along the anterolateral aspect of his right foot. Which of the following electrodiagnostic test finding suggests is most consistent with a diagnosis of isolated radiculopathy in this patient?
1. Normal SNAPs, normal CMAPs, positive sharp waves and/or fibrillations on needle electromyography
2. Abnormal SNAPs, normal CMAPs, positive sharp waves and/or fibrillations on needle electromyography
3. Abnormal CMAPs, normal SNAPs, normal needle electromyography
4. Normal SNAPs, normal CMAPs, normal needle electromyography
1. Normal SNAPs, normal CMAPs, positive sharp waves and/or fibrillations on needle electromyography
- The nerve conduction study is typically normal in lumbosacral radiculopathy.
- This is due to the preservation of the dorsal root ganglion, as the lesion of lumbosacral radiculopathy is typically proximal to the dorsal root ganglion.
- Positive sharp waves and/or fibrillations are typically seen during the needle EMG portion of the test.
- SNAPs and CMAPs on nerve conduction study are normal in lumbosacral radiculopathy.
A 10-year-old boy is brought to the clinic for follow-up. He sustained a hyperextension head injury during a motor vehicle accident five months ago. Vital signs include blood pressure 115/60 mmHg, heart rate 70/min, and temperature 98.6 F (37 C C). During a physical examination, the patient has a full range of motion to his cervical spine and full motor strength to his bilateral upper and lower extremities. The patient has intact sensation to light and painful stimuli to his bilateral upper and lower extremities. He is noted to have decreased vibration and fine touch sensations below the cervical spine level of C7. Which of the following additional features is most likely to be present in this patient?
- Loss of temperature sensation below the level of injury
- Normal gait
- Hyperreflexia
- Difficulty ambulating in the dark
4. Difficulty ambulating in the dark
- Mechanism of injury and clinical findings are all important when making an accurate spinal cord injury diagnosis. In this question, the patient sustained a hyperextension injury, and on physical exam, he had fine touch sensation and vibration sensation loss below cervical spine level C7.
- This patient had intact motor and light touch. This leads one to make the diagnosis of posterior spinal cord injury. Posterior cord injury is defined by the preservation of motor function, pain, and temperature, light touch, but proprioception and vibration sensations and fine touch are lost below the level of the injury.
- The posterior portion of the spinal cord can be damaged either by direct trauma or because of a secondary injury involving the posterior spinal arteries. This syndrome is linked to injuries associated with hyperextension of the neck. Patients with this injury may ambulate, but since they lose proprioception and vibratory sensations, direct visualization of their feet is required during walking. Therefore, they may not be able to ambulate in the dark.
- Loss of proprioception below the injured level clinically results in gait abnormalities. It is important first to make an accurate diagnosis and then know all clinical findings that are present from this diagnosis. Posterior spinal cord syndrome affects the dorsal column of the spinal cord, which is responsible for fine touch, proprioception, and vibration. It would not affect temperature sensation, which is transmitted by the lateral spinothalamic tract and is a common finding of anterior cord syndrome. Hyperreflexia is not a clinical finding of posterior spinal cord syndrome.
