Section 4 Flashcards
A 6-year-old has been admitted to the neurocritical care unit for a new diagnosis of posterior fossa brain tumor status post-resection. She is intubated, sedated, and paralyzed. The neurosurgeons placed an extra-ventricular drain to help with the management of elevated intracranial pressure (ICP). Her ICP monitor has been set at 20 and is draining 2-5 ml/hr. Her heart rate is 85 beats per minute, her blood pressure is 125/90 mmHg, her respiratory rate is set at 25 breaths per minute on the ventilator, and her FiO2 is 30% with an oxygen saturation of 95% as measured by pulse oximetry. Histologic evaluation reports large tumor cells with small round undifferentiated cells with mild to moderate nuclear pleomorphism and high mitotic count. What is the most common cytogenetic abnormality in this type of tumor?
1. Monosomy 6
2. Isochromosome 17q (i17q)
3. Loss of heterozygosity of 9q
4. A gain of chromosome X
2. Isochromosome 17q (i17q)
- The most common cytogenetic abnormality in medulloblastoma is i17q, wherein the short arm (p) is absent, and there is a gain of genetic material from the long arm (q).
- In greater than 50% of patients, deletions in the short arm have been reported, resulting in a genotypic designation as 17pLOH, i.e., loss of heterozygosity of 17p.
- Of note, the tumor suppressor gene, TP53, is located on chromosome 17p. However, mutations in TP53 are a low- frequency occurrence in medulloblastoma.
- Monosomy 6 is associated with the WNT (wingless) medulloblastoma subgroup; LOH 9q is associated with the SHH (sonic hedgehog) medulloblastoma subgroup.
A 50-year-old woman is brought to the hospital after a witnessed seizure. She has complaints of numbness on the right side of the body. She has a history of chronic hypertension. Her current blood pressure is 130/90 mmHg. The motor examination is within normal limits. Sensory examination reveals the inability to recognize objects by touch on the right side. MRI with contrast shows an irregularly enhancing lesion of 2x2 cm in the left parietal lobe. MR spectroscopy shows increased choline. Functional MRI shows the sensory areas in the edematous brain around the tumor. Which of the following is the best treatment plan for this patient?
1. Surgery and anticonvulsant medication
2. Anticonvulsant medication, antiedema measures, and physiotherapy
3. Surgery, antiedema measures, and sensory re-education
4. Anticonvulsant medication and radiotherapy
3. Surgery, antiedema measures, and sensory re-education
- Functional MRI (fMRI) shows the sensory areas in the edematous brain. Therefore, there is a chance of improvement with surgical removal of the tumor and antiedema measures.
- Sensory re-education helps in improving the residual sensory deficit.
- Planning with fMRI helps in preventing the intraoperative damage to the eloquent region, which may result in aggravation of deficits.
- The center for stereognosis is the posterosuperior parietal cortex.
A 55-year-old female presents for a follow-up appointment at the spine clinic. She had an upper cervical spine injury three weeks ago and was placed into a halo brace at that time. Her vitals are taken and include blood pressure 120/80 mmHg, heart rate 80/minute, temperature 100.1 F (37.8 C), and oxygen saturation 99% on room air. Physical exam reveals some foul-smelling drainage and erythema only around the right-sided posterior pin, with no local abscess formation present; otherwise, the patient is neuro- intact throughout. The torque of each pin is checked, and all measured 8 in-lb. The patient had been receiving daily pin site care with hydrogen peroxide, up until several days ago. What is the most appropriate next step in managing this patient’s clinical presentation?
1. Remove the right-sided posterior pin and suture up the pin site
2. Keep the right-sided posterior pin in place and stress the importance for daily pin site care with hydrogen peroxide
3. Tighten the right-sided posterior pin, and stress the importance for daily pine site care with hydrogen peroxide
4. Prescribe an oral antibiotic, keep the right-sided posterior pin in place, and stress the importance for daily pin site care with hydrogen peroxide
4. Prescribe an oral antibiotic, keep the right-sided posterior pin in place, and stress the importance for daily pin site care with hydrogen peroxide
- There are no indications for the right-sided posterior pin to be removed based on the information provided. In the presence of a pin site infection, the pin should only be removed if there is an abscess present at the pin site, or if the pin is loose (with or without an abscess formation). If a pin meets the criteria for it being removed, then a new pin must be placed at a different site. Additionally, the pin site should not be sutured, especially in the setting of infection, as this would not allow for drainage and may promote abscess formation.
- In order to get this question correct, one must first recognize this patient has a pin site infection, without an abscess formation, and that the pin is not loose. Knowing this information, the only correct answer is to leave the pin in place, and prescribe oral antibiotics along with continued daily pin site hydrogen peroxide washing.
- If there was an abscess formation, the pin would have to be removed and replaced by another pin at a different location. If the pin was loose, it would have to be removed and replaced by another pin at a different location as well. A loose pin, in the setting of a pin site infection, should be removed and not tightened.
- When there is a pin site infection, and the pin is not loose, it can remain in place; however, oral antibiotics must be prescribed as well. Therefore, local daily pin site care with hydrogen peroxide (although should be continued) does not completely address the pin site infection. The appropriate steps include prescribing an oral antibiotic. The right-sided posterior pin torque is at eight in- lb, which is the max and appropriate amount of torque needed. Therefore this pin does not need to be tightened, and doing so may cause iatrogenic harm. Additionally, if a pin is loose in the setting of pin site infection, it should be removed and replaced by a pin onto a different site, not tightened.
A 32-year-old female presents for double vision. Her symptoms started about a week ago, and she noted double vision, which is more prominent on looking to her right. Her symptoms are persistent and are now accompanied by headaches. She recovered from flu about a week ago. Her past medical history includes multiple sclerosis. Physical examination shows vital signs within normal limits. Cranial nerve examination show isocoric pupils, briskly reactive to light, and no visual field cuts. Extraocular muscle movement shows her left eye does not adduct past the midline, with horizontal nystagmus on the right eye on when looking to the right. Other cranial nerves are normal. The motor and sensory exam are normal. Which of the following is the most likely location of the lesion?
1. Frontal eye fields
2. Medial longitudinal fasciculus
3. Superior colliculus
4. Occipital lobe
2. Medial longitudinal fasciculus
- In patients with internuclear ophthalmoplegia (INO) there is a disorder of conjugate lateral gaze. The affected eye shows impairment of adduction. With attempts to gaze contralaterally (relative to the affected eye), the affected eye adducts minimally, if at all. The contralateral eye abducts with nystagmus.
- In INO, the divergence of the eyes leads to horizontal diplopia. If the right eye is affected, the patient will see double when looking to the left. Convergence is generally preserved.
- INO is caused by a disruption in the medial longitudinal fasciculus (MLF).
- In young patients, INO is most likely due to multiple sclerosis. In the elderly, it is more commonly caused by a brainstem stroke.
A 53-year-old woman presents to the clinic for evaluation. She underwent a laminectomy for chronic lower backache two years ago. Since then, she has tried multiple analgesic regimens, but her symptoms have persisted. She appears frustrated and tearful. Physical examination reveals restriction of back movements due to pain. The neurological examination is unremarkable. She takes oxycodone daily and hydromorphone- acetaminophen for breakthrough pain. Which of the following complications is most likely to occur in this patient?
1. Chronic kidney disease
2. Chronic liver disease
3. Suicide attempt
4. Schizophrenia
3. Suicide attempt
- The clinical scenario describes a patient with chronic pain.
- Chronic pain leads to significantly decreased quality of life, reduced productivity as well as lost wages, worsening of chronic disease, and psychiatric disorders such as depression, anxiety, and substance use disorders. Patients with chronic pain are also at a significantly increased risk for suicide and suicidal ideation.
- Research has shown the lifetime prevalence for chronic pain patients attempting suicide to be between 5% and 14%; suicidal ideation was approximately 20%. Of the chronic patient patients who commit suicide, 53.6% died of firearm-related injuries, while 16.2% from an opioid overdose.
- The patient’s current medications are unlikely to result in chronic liver or kidney disease. Schizophrenia is not associated with chronic pain syndrome.
An 80-year-old female presented with severe back pain after a ground-level fall two days ago. She states the pain is isolated in her low back and denies any radiation of pain, numbness, or tingling in her lower extremities. On examination, she is tender along the L1 spinous process. X-ray reveals the collapse of the L1 anterior vertebral height by 4mm. The patient is otherwise healthy, and the remainder of her physical exam is benign. She is given a prescription for pain medication and physical therapy. She returns seven weeks later without resolution of her symptoms, and she has been unable to perform her activities of daily living due to the pain. What is the most appropriate next step in management?
1. Continued conservative therapy with the addition of opiate pain medication and rigid orthosis
2. Biopsy of L1 to evaluate for neoplasm, followed by PET and CT scan
3. T11-L3 posterior spinal fusion
4. Percutaneous L1 vertebral augmentation
4. Percutaneous L1 vertebral augmentation
- This patient is presenting with an L1 vertebral compression fracture that is causing debilitating pain despite over six weeks of conservative treatment. At this time, a vertebral augmentation procedure is indicated and should be discussed with the patient.
- Vertebral compression fractures are the most common fragility fractures in the elderly and can cause significant physical limitations due to pain. These injuries occur primarily in osteoporotic bone and are classically associated with low energy mechanisms. They are caused by an abnormal quantity of bone, not quality of bone, leading to a decrease load to failure and propensity to fracture. The majority of these patients can be treated conservatively with multimodal pain control, physical therapy, and a gradual return to activity.
- Vertebral augmentation is a process where cement is injected into the vertebral body at the site of the compression fracture in order to alleviate pain by improving the structural integrity and mechanical stabilization. Two described procedures for percutaneous vertebral augmentation are kyphoplasty and vertebroplasty. Of the two, the only kyphoplasty is a recommended treatment for subacute vertebral compression fractures failing conservative treatment.
- Continuing conservative therapy is an option, but not with the addition of opiate analgesia. This could lead to dependence and adverse effects due to polypharmacy. This patient has no signs of malignancy (constitutional symptoms, weight loss), or imaging findings of lesions in the question stem. Surgical stabilization is not indicated in this patient as her spine is stable, and she is neurologically intact.
A 20-year-old man presents with an intense headache, nausea, and persistent vomiting that has been ongoing for two months. He is now finding it difficult to concentrate while playing his video game station. Examination reveals that he has difficulty with upward gaze and is unable to converge his pupils. He has mild papilledema. The blood work is not very remarkable. What is the most likely cause of the underlying condition?
1. Acoustic neuroma
2. Astrocytoma of the midbrain
3. Pinealoma
4. Aneurysm of the anterior circulation
3. Pinealoma
- A pinealoma is located near vital neural and vascular structures. The position accounts for most of its symptoms.
- When a tumor of the pineal gland occurs, it may present with Parinaud syndrome, which is palsy of upward gaze, failure of convergence, and dissociation of light and accommodation.
- MRI is the preferred radiological modality.
- Other symptoms may include hydrocephalus, precocious puberty, and gait problems.
A 17-year-old patient had been intubated and managed in mechanical ventilation for neurogenic pulmonary edema resulting from a severe head injury. The patient has now shown good neurological improvement, with his motor score improving to 5. The chest x-ray also showed good improvement from that of the previous glass ground appearance. The treating clinician now wants to plan for the extubation of the patient. Which of the following is the best indicator for prognosticating successful extubation in the patient?
1. Positive end-expiratory pressure (PEEP) 8
2. Intracranial pressure (ICP) 20
3. Rapid shallow breathing index (RSBI) 105
4. Normal arterial blood gas (ABG) analysis
3. Rapid shallow breathing index (RSBI) 105
- Rapid shallow breathing index (RSBI) is the ratio of the spontaneous breathing frequency (per minute) and the average tidal volume (liters) of the patient. It should ideally be taken at least three minutes after discontinuing the patient from ventilatory support.
- RSBI of 105 breaths/min/L is taken now as one of the best predictors for prognosticating safe and successful extubation in an intubated patient.
- A meta-analysis study has shown that the sensitivity of the RSBI in successful extubation in intubated patients was as high as 90%.
- A motor score of five is also a reliable indicator for predicting safe extubation, and there is no need for monitoring intracranial pressure in each patient. The normal arterial blood gas analysis is only one of the indicators in the daily assessment of liberation potential.
A 55-year-old female patient who was previously evaluated at the pain management clinic presents for a scheduled lumbar sympatholysis using radiofrequency ablation at the right L3- L4 level. This procedure was planned due to persistent right knee pain as a result of complex regional pain syndrome following a motor vehicle collision five years ago. Past medical history is significant for coronary artery disease, hypertension, type 2 diabetes mellitus, obesity, peptic ulcer disease, and asthma. She received pre- operative clearance for the procedure from her primary care provider two weeks ago. Vital signs are stable, and she is afebrile. As the patient is prepared for the procedure and positioned prone in the fluoroscopy bed, the clinician notices an erythematous area over the right lumbar region, approximately 3x5 cm in size. It is indurated and warm to touch. When questioned, the patient reports she went swimming at a nearby lake with her family a few days ago and attributes the lumbar skin lesion to a bug bite that she has frequently been scratching. Which of the following would be the best course of action?
1. Administer low-dose intravenous diphenhydramine and continue with the planned procedure
2. Administer prophylactic antibiotics such as cefazolin 2 grams and continue with the planned procedure
3. Continue with the planned procedure and refer the patient to follow-up with her primary care provider regarding the observed skin lesion
4. Cancel the planned procedure and refer the patient to follow-up with her primary care provider regarding the observed skin lesion
4. Cancel the planned procedure and refer the patient to follow-up with her primary care provider regarding the observed skin lesion
- The skin lesion described should raise the clinician’s suspicion for a local skin infection, especially given the patient’s medical history, which includes diabetes mellitus.
- Infection at the procedural site is considered a strong contraindication to performing lumbar sympatholysis.
- Relative contraindications include coagulation abnormalities, platelet dysfunction, malignancy near the treatment site, systemic infection or bacteremia, and severe cardiac and/or pulmonary disease.
- Prophylactic antibiotics are not usually indicated for lumbar sympatholytic procedures.
A 65-years-old male complains of right leg pain rated 7/10 of severity. Imaging studies (x-rays and MRI) show severe L4-L5 lumbar stenosis with degenerative scoliosis and grade II spondylolisthesis. The patient has been treated with pain medication and steroid nerve root injection without positive results; he has heard about a decompression surgery alone (without fusion) and asks the clinician about his opinion. Based on the knowledge, what is the best answer for this patient?
1. The decompression surgery alone is a good option for this patient as he has severe lumbar stenosis
2. Decompression surgery with or without fusion is a good option, and both procedures have similar benefits
3. Decompression surgery alone is a relative contraindication to this patient due to scoliosis and spondylolisthesis; therefore, the clinician recommends a decompression and fusion surgery
4. Decompression surgery alone is the best option but has more complications than fusion surgery
3. Decompression surgery alone is a relative contraindication to this patient due to scoliosis and spondylolisthesis; therefore, the clinician recommends a decompression and fusion surgery
- Decompression surgery alone is a good option in severe lumbar stenosis. However, the patient has degenerative scoliosis and spondylolisthesis; both conditions are considered relative contraindications for decompression surgery without fusion.
- Decompression surgery with fusion is the best indication for this patient as he has severe lumbar stenosis with scoliosis and spondylolisthesis.
- Decompression surgery with fusion is the best indication to avoid iatrogenic spinal instability in this patient.
- Decompression surgery alone is contraindicated in this case, as this procedure can increase the risk of spinal instability due to the presence of scoliosis and spondylolisthesis; therefore, a decompression followed by fusion is the best indication for this patient.
A 62-year-old man with a past medical history of alcohol use, 40-pack year smoking history, and diabetes mellitus is admitted to the ICU with a grade 4 subarachnoid hemorrhage (Hunt and Hess scale). Which of the following is the most appropriate screening recommendation for the patient’s siblings?
1. Screening for those with hypertension
2. Screening if one first-degree relative has a history of ruptured intracranial aneurysm and the time of presentation is 40 years of age
3. Screening if there is a past medical history of ischemic stroke
4. Screening if two first-degree relatives have a history of ruptured intracranial aneurysm
4. Screening if two first-degree relatives have a history of ruptured intracranial aneurysm
- Screening for intracranial aneurysms is required if there is a family history of two or more first-degree relatives with ruptured intracranial aneurysms.
- Screening is also required if there is a past medical history of autosomal dominant polycystic kidney disease.
- Individuals with type IV Ehlers-Danlos syndrome, hereditary hemorrhagic telangiectasia, neurofibromatosis type 1, tuberous sclerosis, alpha1-antitrypsin deficiency, coarctation of the aorta, bicuspid aortic valve, fibromuscular dysplasia, pheochromocytoma, and Klinefelter syndrome are at a greater risk of developing intracranial aneurysms, and screening should be considered in these patients.
- Screening for individuals with one first-degree relative with ruptured intracranial aneurysm doesn’t appear to be helpful
A 23-year-old man is brought to the outpatient clinic with a complaint of vague occipital headaches for the past 2 months. On examination, he is neurologically intact. A computed tomogram shows some hyperdensities in the right cerebellum. He undergoes a computed tomogram, which shows an arteriovenous malformation of size 7 x 5 cm involving the right cerebellar hemisphere and nuclei with venous drainage into the vein of Galen. Which of the following is the appropriate method of management?
1. Clinical observation and repeat angiogram every 5 years
2. Surgical excision as the lesion is associated with a high risk of a life-threatening bleed
3. Radiosurgery
4. Angioembolization of the nidus
1. Clinical observation and repeat angiogram every 5 years
- The patient is having an arteriovenous malformation (AVM) involving the right cerebellar hemisphere.
- Since it involves the eloquent area with a size >6 cm with deep venous drainage, the Spetzler Martin (SM) grade is V.
- SM grade V AVMs are managed by observation and repeat angiogram every 5 years.
- Treatment is planned only if there is progressive neurological deficits, steal-related symptoms, or associated aneurysms.
A 24-year old male presents to the clinic with excessive daytime sleepiness, memory problems, and trouble sleeping at night. He describes a recent episode where he was watching a funny TV show and then suddenly collapsed, going completely limp, while laughing at a joke. Which of the following structures is most likely involved in the patient’s pathology?
1. Basal Ganglia
2. Carotid Baroreceptor
3. Pedunculopontine tegmentum
4. Caudate nucleus
3. Pedunculopontine tegmentum
- Cataplexy, excessive daytime sleepiness, memory problems, and sleep issues are all supportive of a diagnosis of narcolepsy.
- Narcolepsy is thought to be related to dysfunction of the reticular activating system.
- The pedunculopontine tegmentum is a component of the reticular activating system and contains primarily cholinergic neurons.
- The reticular activating system is integral in human attention, arousal, and the modulation of muscle tone.
A 22-year-old man is brought to the emergency department after suffering a motorcycle collision. On physical examination, the patient is hemodynamically stable and has a single deep abrasion of the left leg. Surgical lavage and debridement of devitalized tissue is performed. A segmental injury of the common peroneal nerve is encountered and is repaired using a sural nerve graft from the same leg. Which of the following best identifies the maximum graft length at which any functional recovery is expected?
1. 3 cm
2. 6 cm
3. 9 cm
4. 10 cm
2. 6 cm
- Nerve grafts longer than 6 cm usually provide poorer outcomes since the irrigation of the nerve decreases with its length.
- In nerve gaps longer than 6 cm, the use of vascularized nerve grafts is recommended since they can provide better perfusion to the transferred tissue.
- The length of the nerve gap should be considered at the maximum range of motion of the articulation that the affected nerve transverses.
- Total recovery of the motor, sensitive, and autonomic functions of the reconstructed nerve is never achieved, although the shorter the gap, the better the outcomes.
A 17-year-old boy presents to the emergency department after being hit by a car. The patient is complaining of headache, double vision, and dizziness. His past medical history is insignificant except for an allergy to contrast media. On examination, vital signs are within normal limits. His pupils are isocoric and equally reactive to light. There is nystagmus more prominent when looking to the right. No facial asymmetry is noted. There are no motor or sensory deficits. A finger-to-finger and finger-to-nose test demonstrate dysmetria on the right side. The patient cannot undergo a CT angiogram as he has a severe allergy to contrast. An intracranial and neck Duplex scan is ordered. Which of the following findings would be expected from this study?
1. Dissection of the internal carotid artery
2. Dissection of the basilar artery
3. Abnormal flow via the internal carotid artery
4. Abnormal flow in the vertebral artery
4. Abnormal flow in the vertebral artery
- The patient’s presentation is suspect for vertebral artery dissection. The Duplex ultrasound is rarely normal in a patient with vertebral artery dissection. Flow abnormalities will be seen the majority of the time.
- Duplex ultrasound shows abnormal flow in 95% of vertebral artery dissections.
- Dissection or signs specific to a dissection, such as segmental dilation of the vessel and eccentric channels, are seen only 20% of the time.
- Using Duplex ultrasound, one should be able to visualize the vertebral arteries.
A 65-year-old man has been brought to the hospital following the sudden onset of altered sensorium, difficulty in speaking, and weakness in the right half of his body. The patient had a motor score of 5, and both the pupils were equal and reacting to light. The CT scan of the head revealed features of left-sided chronic subdural hematoma with a gross midline shift. He had a history of alcohol abuse. The treating physician decided for a burr hole evacuation of the hematoma. A single parietal region burr hole was made, and the cruciate dural incision was given, which revealed machinery oil-like hematoma egressing under high pressure. Thorough irrigation with normal saline was made until the clear fluid was visualized. The wound was closed. In the postoperative period, the patient shows sudden deterioration in his motor score to two, with anisocoria developing on his left pupil. What is the most likely etiology for this sudden adverse event occurring in the patient following the surgery?
1. Seizure
2. Rebleed
3. Tension pneumocephalus
4. Hypoglycemia
3. Tension pneumocephalus
- The presence of pneumocephalus is one of the frequent occurrences following the burr hole evacuation of the chronic subdural hematoma. It has been seen in up to 44% of cases in the immediate postoperative CT images following such procedures.
- The small burr hole allows for the atmospheric air to enter into the skull secondary to the egress of the subdural hematoma, which can sometimes lead to the occurrence of tension pneumocephalus. This is more frequent among patients with a history of chronic alcohol abuse that leads to brain atrophy. The failure of brain expansion to the surface increases the odds of developing pneumocephalus.
- The occurrence of this complication can be prevented by lowering the head end of the bed while evacuating the hematoma along with liberal saline irrigation. The placement of drain is also advocated to prevent the pneumocephalus. High flow oxygen in the postoperative period is recommended to manage most cases with pneumocephalus, except in cases with tension pneumocephalus.
- The rebleed is rare since the hemostasis was assured while closing of the wound through copious saline irrigation. The patient did not show features of any seizurogenic activities in the patient.
A 50-year-old woman is being evaluated for persistent headaches. She is found to have a vascular lesion with direct drainage from arterial branches from the middle meningeal artery into a cortical vein. Which of the following possible factors best indicates surgical resection as a treatment option?
1. Multiple medical comorbidities
2. Accessibility via transarterial or transvenous approach
3. Benign natural history based on Cognard classification system and lack of symptoms
4. Failure of prior endovascular embolization to completely occlude the lesion
4. Failure of prior endovascular embolization to completely occlude the lesion
- Surgery, endovascular embolization, and stereotactic radiosurgery are options for the intervention for dural arteriovenous fistulas. Surgery may be considered as a first-line treatment, though endovascular treatment should also be considered as first-line therapy. Failure of prior endovascular embolization to completely occlude a dural arteriovenous fistula is a reason to consider open surgical resection.
- Observation with clinical and radiologic follow up is considered for most patients with asymptomatic and low-grade dural arteriovenous fistulas. Surgical resection is typically considered as a treatment option for a higher grade and symptomatic lesions.
- Endovascular embolization may be performed through a transvenous approach, transarterial approach, direct access, or a combination of the above. When there is satisfactory endovascular access to the fistulous point of a dural arteriovenous fistula, endovascular embolization should be considered as a treatment option.
- Significant medical comorbidities should be considered when deciding treatment of dural arteriovenous fistulas, as they impart higher risk for open surgical resection under general anesthesia.
A 54-year-old right-handed male presents with intractable headaches for the past five weeks. His workup reveals a large right temporal tumor. He is an aircraft pilot and would like surgical resection so he can resume his work as soon as possible. Which visual deficit may occur regarding surgery of a lesion in this region?
1. He may develop bilateral left-upper visual field deficit
2. He may develop bilateral right-upper visual field deficit
3. He may develop bilateral left-lower visual field deficit
4. He may develop bilateral right-lower visual field deficit
1. He may develop bilateral left-upper visual field deficit
- Lesions of the optic radiation in Meyer’s loop cause a bilateral upper quadrant visual field deficit of the contralateral side.
- Visual information traveling from the inferior quadrant of the retina travel through the anterior temporal lobe under the inferior horn of the lateral ventricle.
- Surgical resection of over 3cm of the temporal lobe will lead to a visual field deficit.
- The quality of life is usually not affected in patients suffering from post-surgical homonymous superior quadrantanopia.
A 46-year-old man presents to the clinic with a complaint of pain in the neck along with a tingling sensation in the right upper forearm after a history of a fall from a height. The radiograph reveals fused vertebrae and a radiolucent line in the C6 vertebra with displacement. An initial set of labs is significant only for HLA-B27 positivity. What is the most appropriate management strategy for this patient?
1. Rigid cervical orthosis
2. Open reduction and instrumentation
3. Halo traction
4. Conservative management
2. Open reduction and instrumentation
- This vignette reveals the diagnosis of ankylosis spondylitis spine with fractured C6 vertebrae.
- The spine fracture in patients with ankylosing spondylitis is always a three-column fracture.
- Three-column fractures should always be fixed and operated with posterior instrumentation.
- Rigid orthosis is indicated in undisplaced fractures of the cervical spine in normal patients.
Which neurons should be stimulated by the spinal cord stimulation implant in a 55-year-old patient with bilateral lower extremity pain?
1. Dorsal root
2. Anterior root
3. Sympathetic nerves
4. Stellate ganglion
1. Dorsal root
- Dorsal root stimulation alleviates bilateral lower extremity pain.
- A spinal cord stimulator supplies pulsed electrical signals to the spinal cord. It is used to control chronic pain and spinal spasticity or to augment standing and stepping capabilities. Spinal cord stimulation (SCS) can produce substantial analgesia.
- The most common use of SCS is in failed back surgery syndrome in the United States and peripheral ischemic pain in Europe. It is indicated for the treatment of inoperable ischemic limb pain. It can modulate the sympathetic nervous system and increase norepinephrine release in refractory angina pectoris, decreasing the frequency of angina attacks. SCS is used to treat patients with frequent migraines, using electrodes implanted in the bilateral suboccipital region.
- SCS is useful when other forms of therapy fail. It is invasive and may be associated with complications such as infection, bleeding, and dural puncture. SCS interaction with diathermy, pacemakers, MRI, and therapeutic ultrasound can result in unexpected changes in stimulation, serious patient injury or death, or device failure.
A 55-year-old man is brought in by emergency medical services (EMS) after being involved in a motor vehicle accident. On examination, the patient responds inconsistently and specifically to external stimuli, and he withdraws to painful stimuli. Which of the following would also be expected in this category of the Rancho Los Amigos scale (RLAS)?
1. Responds more to his wife
2. Responds more to the medical staff
3. Ability to follow simple commands
4. Tremor, athetosis, and involuntary movements
1. Responds more to his wife
- A patient with a Rancho Los Amigos score of 3 demonstrates only localized responses to external stimuli inconsistently. Voluntary motor testing will be unavailable for the therapist.
- The patients will respond more to familiar people (friends and family) versus strangers.
- When assessing motor control in these patients, only reflexes, rigidity, and tone can be assessed.
- Withdrawal secondary to pain would be a sensory reflex evaluation. The patient is unlikely to be able to follow simple commands.
A 6-month-old infant girl was recently evaluated for increased fussiness associated with a rapidly growing head circumference. Between her four months and six-month well-child check-up, her head circumference rose from 50% to 90%. A subsequent head CT revealed enlarged ventricles with a large mass in the posterior fossa. What is the most common histologic subtype for this type of brain tumor?
1. Classic
2. Desmoplastic or nodular
3. Large-cell or anaplastic
4. Melanotic and medullomyoblastoma
1. Classic
- In classic medulloblastoma, sheets of small round cells possessing a high nuclear-to-cytoplasmic ratio are noted. They have a high invasive tendency and occasional neuroblastic differentiation. The classic type constitutes approximately 70% of medulloblastomas.
- Nodules of tumor cells displaying neurotic differentiation on a collagen-rich matrix characterize the desmoplastic variant. These tumors are less aggressive than the classic variant and account for 15% of medulloblastomas.
- Large-cell anaplastic medulloblastomas, as the designation suggests, demonstrate features of anaplasia, including large tumor cells with abundant cytoplasm, pleomorphic nuclei, and prominent nucleoli. These tumors are typically located in the cerebellar vermis and are highly aggressive, demonstrating the high mitotic and apoptotic activity with large areas of necrosis. Consequently, the prognosis is especially poor with short survival times after diagnosis. They constitute approximately 10% of medulloblastomas.
- Melanotic and medulloblastoma are rare and make up the remaining 5% of medulloblastomas.
A 48-year-old presented to the emergency department (ED) following a motor vehicle accident (MVA). He underwent primary and secondary surveys, which revealed tenderness over the neck region and painful neck rotations. The rest of the systemic and neurological examinations were normal. He underwent a CT scan of the head and cervical spine as part of his evaluation. CT cervical spine revealed an anterior C1 arch fracture with extension into the foramen transversarium. Which of the following is the most rational approach in the management of the patient?
1. Reassurance
2. Occipitocervical fixation
3. C1-C2 posterior fixation
4. CT vertebral artery angiography
4. CT vertebral artery angiography
- Though the patient has a stable C1 fracture, there is an extension of the fracture into the foramen transversorium harbingering the risk of blunt vertebral artery injury.
- Such injury has more than a 20% risk of developing ischemic strokes in the patient. So timely institution of anticoagulation therapy is of paramount importance in high-risk cohorts.
- CT vertebral artery angiography thereby enables proper dichotomization of high-risk patients that require early anticoagulation therapy.
- Fusion for C1 fracture is indicated only in cases of unstable features such as Jefferson subtypes or those with comminuted later mass fracture.
A 3-day-old neonate develops a fever, irritability, and floppy posture in the immediate postpartum period. The mother has had numerous sexual partners without barrier protection or prenatal care. The baby was born 4 hours after an amniotic sac rupture. Lumbar puncture is done, which reveals a white blood cell count of 1000 per mL with neutrophilic predominance. What is the most likely etiology?
1. Escherichia coli
2. Streptococcus agalactiae
3. Haemophilus influenzae
4. Listeria monocytogenes
2. Streptococcus agalactiae
- The signs and symptoms in this infant are suggestive of meningitis. CSF findings are indicative of bacterial meningitis. Streptococcus agalactiae (group B streptococci) is the most common cause of neonatal meningitis in the immediate postpartum period.
- It is most prevalent in young women with multiple partners and is most likely to infect the neonate during a protracted delivery.
- E. coli is the second most common cause of neonatal meningitis. Its relative incidence is increasing due to screening for GBS and prophylaxis.
- Listeria is a less frequent cause of neonatal meningitis. Haemophilus influenza and Neisseria meningitides rarely cause neonatal meningitis.
A 72-year-old man presents with a one-year history of lower back pain that is gradually getting worse. He now describes the pain as a six out of ten. He has a past medical history of lumbar disc herniation for which he had a discectomy one year ago, and the pain got better at first, but it never resolved completely. He also says he was prescribed several analgesics during this time with no relief. A spinal cord stimulator (SCS) is considered as a treatment option for this patient. Which of the following is a rare complication of the procedure?
1. Lead migration
2. Lead fracture
3. Cerebro-spinal fluid leakage
4. Seroma
3. Cerebro-spinal fluid leakage
- The complication rate following spinal cord stimulator implantation is relatively high. The most common complications are due to the hardware malfunction, such as lead migration.
- The puncture of the dura can occur during lead placement, causing a cerebrospinal fluid leak, but it is rare.
- The puncture of the dura can occur during lead placement, with headaches occurring in up to 70 percent of cases.
- Lead fractures can occur in above nine percent of cases being a strenuous physical activity, one of the causes.
A 68-year-old male with alcohol use disorder presents with mental status changes, gait abnormalities, and confusion, and he tells you he just had lunch with the president. Which ocular feature would one expect to find in this patient?
1. Optic neuritis
2. Diplopia
3. Glaucoma
4. Exposure keratopathy
2. Diplopia
- The individual with Wernicke Korsakoff syndrome will usually present with ocular disturbances which may include diplopia, painless vision loss, or strabismus.
- Gait abnormalities include a wide-based short stepped gait and an inability to stand or ambulate without assistance.
- Mental status changes include apathy, paucity of speech, and indifference to the environment.
- As the disorder progresses, other symptoms that may develop include agitation, anger, hallucinations, and confabulations.
A 76-year-old female comes to the clinic for a follow-up visit and is found to have no vision on the left eye. She is known to have a left optic nerve sheath meningioma since she was in her fifties. At that time, she had a mild visual loss and was not recommended to have surgery. At present, she has no pain, and no proptosis, the optic nerve is atrophic. Vision in the right eye is 20/30 with prescription eyeglasses. Magnetic resonance imaging showed a minimal increase in the size of the tumor. Which is the best management in this patient?
1. Stereotactic radiotherapy to stop the growth
2. Continue observation
3. Surgical removal of the nerve and tumor to prevent spread posteriorly
4. Chemotherapy with estrogen antagonists
2. Continue observation
- If the eye with the optic nerve sheath meningioma (ONSM) is blind, and the tumor is confined to the orbit, the patient should be observed as they grow very slowly. Some surgeons advocate surgically resecting the tumor to avoid extension to other areas, but this patient is 76-year-old.
- Observation is the acceptable measure in cases where the visual function is intact or remains stable, especially in patients who maintain a central visual acuity of 20/50 or better.
- Stereotactic radiotherapy has been used as an alternative to surgery.
- Surgical resection can be justified in cases of disfiguring proptosis where the visual function has significantly decreased or in cases of intracranial extension.
A 65-year-old female patient presents to the hospital with complaints of severe headaches associated with nausea and vomiting on awakening for the past few months. She also reports loss of weight and loss of appetite. She recalls having radiation therapy ten years ago for some growth, but can not precisely remember the diagnosis. On examination, she is found to have a heart rate of 100 beats/min, a blood pressure of 100/70 mmHg, respiratory rate of 20/min, and 95 % oxygen saturation on room air. Lab values, including CBC and metabolic profile, are within the normal range. CT head shows an irregular mass-like lesion, which was not present in her previous imaging four years ago. MRI revealed a 3 cm irregular mass in the left temporal lobe. Information regarding which of the following is most likely to help in establishing a diagnosis in such patients?
1. Previous radiation
2. Prior surgeries
3. Family history
4. Smoking and alcohol history
1. Previous radiation
- Glioblastoma multiforme is the most common aggressive primary cranial nervous system tumor. Usually more common in older men and African American race.
- Studies have shown that a previous history of irradiation in early life is a risk factor for GBM. Although, in most cases, risk factors are not identified.
- It is important to take a careful history, including a prior history of irradiation, to assess for risk factors.
- No convincing evidence exists regarding associations of GBM with family history, smoking, or alcohol history.
A 30-year-old male golfer has had severe posterior right leg pain for the last year. He has failed conservative measures, and his right leg pain is interfering with golf and daily activities. He denies significant back pain. His priority is relief of pain while preserving his ability to play golf, if possible. MRI demonstrates a large L5/S1 disc herniation eccentric to the right side with severe foraminal stenosis, and preservation of disc space height. What is the most appropriate management strategy for this patient?
1. Advise conservative treatment
2. L5/S1 right-sided microdiscectomy
3. L5/S1 transforaminal lumbar interbody fusion (TLIF)
4. L5/S1 anterior Lumbar Interbody Fusion (ALIF)
2. L5/S1 right-sided microdiscectomy
- While conservative management is generally best in young patients, this must be taken on a case by case basis. Here, the patient’s activities of daily living are severely impaired, and he has a clear, localized pathology to explain his symptoms. Hence, surgery is reasonable.
- For cases with isolated, unilateral disc herniations without facet degeneration or instability, decompression alone without fusion is a suitable choice.
- An anterior approach may not fully address his symptoms as his disc space height was preserved on imaging. Hence, posterior microdiscectomy is a better choice for direct pathology access.
- Microdiscectomy does carry a small (~10%) risk of recurrence, which may need further discectomy and fusion (TLIF) in the future, but given his radicular symptoms and isolated imaging findings, microdiscectomy now is more appropriate than TLIF.
A patient with metastatic squamous cell carcinoma has transfacial/transnasal ethmoidectomy. Clear rhinorrhea developed postoperatively that was treated with a lumbar puncture to remove 20 mL of fluid daily for three days. The patient later suddenly became confused and lethargic. She has a motor score of 5 with a verbal response of only 2. Her CT head revealed a huge bifrontal hypodense lesion causing subfalcine herniation. What is the most important initial treatment for the patient?
1. Craniotomy
2. Observation
3. Administration of 100 percent oxygen
4. Needle aspiration
3. Administration of 100 percent oxygen
- The clinical vignette is classical of a tension pneumocephalus.
- The first step in treatment should be 100 percent oxygen.
- Using 100 percent oxygen allows for the reduction of pneumocephalus owing to its diffusion mediated by nitrogen gradient (80% in pneumocephalus) towards blood (0% in 100% oxygen) and its subsequent disposal of the lungs.
- Craniotomy or burr bole is justified in tension pneumocephalus with significant brain herniation encompassing a major threat to the patient’s life.
A 16-year-old patient is being planned for surgical excision of the intramedullary tumor of the conal region of the spinal cord. The patient is worried about the risk of losing his bowel function following the surgery. What intraoperative modality will help in safeguarding from this probable complication during the surgical resection of the tumor?
1. Motor evoked potential
2. Somatosensory evoked potential
3. Bulbocavernosus reflex monitoring
4. Intraoperative MRI
3. Bulbocavernosus reflex monitoring
- The preservation of bladder and bowel function is of paramount importance while operating on an intramedullary tumor in the conal region.
- Intraoperative assessment of the bulbocavernosus reflex is a valid tool in safeguarding the bowel function while performing surgical excision of such a tumor.
- Electromyography from anal sphincters following bulbocavernosus reflex helps in the intraoperative assessment of the integrity of the bowel function.
- Motor and somatosensory evoked potentials can be used as an adjunct, but they play no role in assessing bladder bowel function. Intraoperative MRI is technically demanding and also requires tractography in safeguarding the relevant tracts.
A 38-year-old laborer presents with pain along the lateral aspect of his elbow. He first developed an odd ache three months ago and has now noticed that he has weakness in his hands and fingers. He denies any recent injury to the arm. He is a smoker and drinks alcohol socially. He takes acetaminophen for muscle pain. Examination reveals that he has preserved wrist extension but there is a marked loss of finger extension. Wrist flexion is within normal limits. There is no sensory loss. Nerve conduction studies are unremarkable, and an MRI did not show any mass lesion. Based on this presentation, where is the pathology is most likely located?
1. Dorsum of the wrist
2. Guyon canal
3. Arcade of Frohse
4. First rib
3. Arcade of Frohse
- The posterior interosseous nerve is an extension of the radial nerve as it course on the posterior side of the forearm. The posterior interosseous nerve is motor to the wrist, finger extensors as well as the supinator muscle.
- Sometimes the posterior interosseous nerve can become entrapped at the arcade of Frohse. The nerve often gets entrapped during repetitive supination and be associated with lateral epicondylitis.
- The patient may present with weakness in wrist and finger extension without any sensory loss. Management includes rest and modification of hand activities.
- If there is no improvement after 3-6 months of extensive conversative management, surgical decompression may be indicated.
A 65-year-old male presents to the emergency department following a high-velocity motor vehicle collision. On arrival, his Glasgow coma scale (GCS) is 6/15. Computed tomography (CT) of the head reveals diffuse cerebral edema. His cervical CT shows a fracture of the C1 vertebra with a concomitant teardrop fracture of the C6 vertebral body. Which of the following findings on magnetic resonance imaging (MRI) scan of the cervical spine can potentially have the most significant impact on the management of the patient?
1. Odema over the posterior ligament complex
2. Hyperintensity posterior to the dens in T2W and STIR sequences
3. Hypointense marrow of the lateral mass of C1 on T2W MRI
4. Concomitant traumatic disc with indentation of the anterior subarachnoid space only
2. Hyperintensity posterior to the dens in T2W and STIR sequences
- The most important factor governing the management of C1 fractures is the intactness of the transverse atlantal ligament (TAL). The TAL can be assessed indirectly on plain radiographs and CT scans. However, the direct assessment of the ligament can only be made on MRI.
- Axial CT scan can reveal bony avulsion injuries of the lateral mass. MRI cervical spine is the best modality to diagnose any damage to this vital ligament. T2WI and STIR (short tau inversion and recovery) sequences can reveal hyperintensity of the ligament at the insertional or intrasubstance level.
- The rule of Spence is based on the assessment of the unilateral or bilateral overhang of the C1 lateral mass over the C2 superior articular process on an open mouth anteroposterior (odontoid) radiograph. If the combined overhand exceeds 6.9 mm (or 8.1 mm after correction for magnification errors), it indicates a rupture of TAL.
- On lateral plain cervical radiographs, atlantodens interval (ADI) greater than 3 mm in adults and 5 mm in the pediatric population indicates TAL injury.
A 44-year-old male patient has noticed progressive weakness in both legs and difficulty in climbing steps during the last month. He recalls doing a lot of flexion and extension movements 2 months ago while helping his sister move to another apartment. He is an intravenous illegal drug user with negative HIV testing. He has numbness in the testicular area. On exam, he has weakness of plantar flexion on the left foot and dorsiflexion on the right. Cremasteric reflex is absent. Upon further questioning, he says that he is unable to have an erection in the last month. A magnetic resonance imaging is ordered and is reported with a lesion in the L2 spinal canal area with enhancement upon contrast administration. It has a dumbbell-shape appearance extending to the right paraspinal area. Which is the most probable diagnosis?
1. Spinal epidural abscess
2. Meningioma
3. Massive herniated lumbar disc
4. Schwannoma
4. Schwannoma
- Schwannoma commonly have a dumbbell-shape due to their propensity to grow out through the neural foramina.
- A spinal epidural abscess usually arises as a complication of discitis or vertebral osteomyelitis. Symptoms can be acute as they can cause venous thrombophlebitis with ischemia of the spinal cord.
- Massive herniated lumbar disc is one of the principal causes of cauda equina syndrome, but it is usually associated with the intervertebral disc space and does not exit through the foramen forming a dumbbell-shape appearance.
- Meningioma may arise anywhere along the lumbar spinal canal and often have a dural tail.
A 65-year-old male presents for follow-up of neck pain radiating into his right arm that has been ongoing for the past three months. The symptoms have not responded to conservative management. An MRI of the cervical spine is obtained for further evaluation of the patient’s underlying pathology. Which of the following findings is most likely to be present on his MRI?
1. Ligamentum flavum atrophy
2. Increased cervical lordosis
3. Osteophyte formation
4. Increased disc height
3. Osteophyte formation
- The patient’s symptoms are likely caused by nerve root compression in the setting of cervical spondylosis.
- Disc desiccation leads to a loss of disc height and can be accompanied by a disc herniation.
- Alteration in load distribution across the cervical spine results in loss of cervical lordosis, which in turn contributes to overloading of the uncovertebral and facet joints, triggering osteophyte formation.
- Altered load balance leads to bony and ligamentous hypertrophy and ossification.
A 22-year-old woman presents with severe back and bilateral leg pain. The patient is a professional gymnast. She says the pain gets worse after practice. She has no past medical history. The diagnosis of lumbosacral spondylolisthesis at L5/S1 is made, and she undergoes a laminectomy, partial correction of the deformity, and instrumented fusion. Which of the following postoperative neurological complications is most likely to occur in this patient?
1. Weakness of the ankle extension
2. Weakness of great toe extension
3. Weakness of ankle plantarflexion
4. Bowel or bladder dysfunction
2. Weakness of great toe extension
- Lumbosacral spondylolisthesis is seen in 4% to 6% of the population, particularly in people engaging in sports requiring back hyperextension activity (gymnasts, footballers, weight lifters). The majority of the slips occur at the L5/S1 level as the forces going through the lumbar spine are the greatest at that level, and facets are oriented in a more coronal fashion.
- As the lumbar spine L5 nerve root exits below the L5 pedicle, it is most commonly affected by the slip. The reduction of high- grade slips is controversial; nevertheless, the same nerve root is usually affected. The weakness of the ankle extension would correlate with L4 nerve root weakness.
- The clinical scenario suggests a higher grade of spondylolisthesis that was possibly treated with reduction and fusion. As the L5 nerve root exits below the L5 pedicle, it is at greatest risk of injury and would present with a weakness to great toe extension.
- Ankle plantarflexion is mainly supplied by the S1 nerve root and is not the most commonly affected in cases of L5/S1 spondylolisthesis. Although bowel and bladder dysfunction may occasionally be present in patients with advanced L5/S1 spondylolisthesis, if it presents as a new finding in the postoperative period, it should be immediately investigated to exclude postoperative causes of cauda equina syndrome like a hematoma.
A 65-year-old male presented to the emergency department following a high-velocity motor vehicle accident. He is intubated on arrival with a GCS of E2V2M4. He has already undergone CT head, which reveals diffuse cerebral edema. His cervical CT reveals a fracture of the atlas vertebra with a concomitant teardrop fracture of the C6 vertebral body. With regard to the management of the C1 fracture, which of the following findings on the MRI scan can potentially have the greatest impact?
1. Significant bony edema over the posterior ring of C1
2. Hyperintense region just adjacent to the right lateral mass of atlas on T2WI MRI
3. Significant hyperintense marrow on T2WI MRI within the lateral mass of C1
4. Presence of hematoma in the anterior anterior epidural space, causing thecal sac indentation
2. Hyperintense region just adjacent to the right lateral mass of atlas on T2WI MRI
- The most important factor governing the management of C1 fractures is the intactness of transverse atlantal ligament (TAL). The TAL can be assessed indirectly on plain radiographs and CT scan. However, the direct assessment of the ligament can only be made on MRI.
- Axial CT scan can reveal bony avulsion injuries of the lateral mass. MRI cervical spine is the best modality to diagnose any injury to this vital ligament. T2-WI and STIR (short tau inversion and recovery) sequences can reveal hyperintensity of the ligament at the insertional or intra-substance level.
- The rule of Spence is based on the assessment of the uni- or bilateral overhang of the C1 lateral mass over the C2 superior articular process on open mouth anteroposterior (odontoid) radiograph. If the combined overhand exceeds 6.9 mm (or 8.1 after correction for magnification errors), it indicates a rupture of TAL.
- On lateral plain cervical radiographs, atlanto-dens interval (ADI) greater than 3 mm in adults and 5 mm in pediatric population indicates TAL injury.
A 36-year-old man is a restrained driver in a high- speed motor vehicle collision. He arrives at the trauma bay alert and oriented but complaining of chest pain. He is found on cross- sectional imaging to have an aortic transection extending from the distal aortic arch to the hiatus. Which of the following interventions is most likely to improve postoperative morbidity following repair, given the extent of the injury?
1. Right tube thoracostomy
2. Preoperative lumbar puncture
3. Preoperative spinal drain placement
4. Simultaneous carotid-subclavian bypass
3. Preoperative spinal drain placement
- Spinal drain placement, often by neurosurgery, allows for decompression of the spinal cord. In this patient, an extensive stent graft is required that will cover many branches from the aorta to the anterior spinal cord.
- This places the patient at high risk for spinal cord ischemia and resultant paralysis. The best practice to minimize this complication is spinal drain placement, allowing for decompression postoperatively.
- During the assessment of the blunt trauma patient, bilateral chest tubes may be placed for pneumothorax or hemothorax. A left-sided effusion on an initial chest X-ray is a non-specific finding that, with a widened mediastinum, may represent an aortic transection. This should be verified with a CT angiogram.
- Placement of the chest tube would not treat the aortic injury. Lumbar puncture would not provide a long enough benefit of spinal decompression. Although carotid-subclavian bypass may be required in about 40% of patients following coverage of the left subclavian artery during stent-graft placement, this is often a staged procedure. Additionally, this patient’s injury is distal to the great vessels. Occasionally, coverage of the left subclavian is necessary for a distal injury to obtain an adequate seal at the proximal stent graft.
A 43-year-old man is brought to the emergency department after a referral for the management of diabetic ketoacidosis. He has a history of type 1 diabetes, being on regular insulin since childhood. His major complaints are high-grade fever and severe headache for the past 5 days. He was prescribed amoxicillin for suspected sinusitis. His girlfriend reports that he has had decreased food intake in the past 3-4 days, and he had also skipped his regular medicines due to extreme lethargy. He also reports severe nausea and vomiting, along with mild breathing difficulty for the past 8 hours. Examination reveals an unconscious patient in a gasping state. He is immediately intubated and artificially ventilated. Further examination reveals proptosis, reddish discoloration, blackish eschar, and swelling of his right eye. His right pupil is fixed and dilated. His bedside blood glucose is 510 mg/dL, and ketones are strongly positive. The base excess is -14 mE/L. Treatment for diabetic ketoacidosis is initiated. He is hemodynamically stable and saturating 98% on room air. A T2 weighted MRI with Fat Sat sequence reveals soft tissue densities in the right sinuses and orbit, and gadolinium contrast evaluation confirms thrombosis in the right cavernous sinus. Sporangia and rhizoids were visualized with lactophenol blue staining of the tissues obtained from debridement. Which of the following is the next best step in the management of this patient?
1. Liposomal amphotericin B
2. Amphotericin B
3. Posaconazole
4. Voriconazole
1. Liposomal amphotericin B
- This young patient in diabetic ketoacidosis with evidence of sinus/ orbit and cavernous sinus involvement merits a high consideration for rhino-orbital cerebral mucormycosis. The suspicion or diagnosis of rhino-orbital cerebral mucormycosis is a medical as well as surgical emergency since it carries high morbidity & mortality even with appropriate treatment. IV liposomal amphotericin is initiated immediately at a dose of 5 mg per Kg body weight per day, with many clinicians going up to a dose of 10 mg per Kg body weight/day. Surgical debridement is planned immediately.
- Extensive surgical debridement is to be planned at the earliest. This will help to arrive at an early tissue diagnosis via frozen section specimens. Tissue PCR techniques also will help in reaching a diagnosis. Surgical debridement is also expected to reduce the fungal load. Extensive exploration and debridement of sinuses along with orbital decompression or exenteration is usually done. Local installation of amphotericin is often done in debrided cavities. The intracranial disease is also debrided as much as feasible. The role of surgical exploration and debridement in intracranial involvement is a bit controversial since many experts believe that mortality is inevitable. However, there are case reports of survival in early intracranial involvement.
- Liposomal amphoterin B has better tissue penetration and minimal renal toxicities compared to parenteral amphotericin B.
- IV posaconazole or isavuconazole is used only when the patient is not tolerating amphotericin or is not responding to amphotericin. They are used as a step-down oral continuation therapy agent, only after many weeks of IV amphotericin therapy has resulted in clinical improvement in the given patient.
A 3-month-old female infant is being evaluated due to progressive head enlargement. She was born after a normal delivery, although the 23-week sonogram showed a minimal cortical mantle in which the hemispheres were replaced with a fluid material. Her head has been increasing in circumference, but the fontanelle is not tense. Which of the following investigations is most likely to identify the etiology of the patient’s condition?
1. Digital subtraction angiography
2. Computed tomographic scan
3. Ultrasound
4. Brainstem auditory evoked response
1. Digital subtraction angiography
- The patient most likely has hydranencephaly. Most studies suggest that the damage caused to the brain is related to early internal carotid artery occlusion. As such, hydranencephaly is categorized into a group of circulatory developmental encephalopathies.
- Digital subtraction angiography is used in some cases to evaluate the patency of the internal carotid arteries.
- The anomaly presenting in hydranencephaly follows the anatomic distribution of the brain supplied by the internal carotid artery. Structures supplied by the posterior circulation (cerebellum, brain stem, thalamus, basal ganglia, and choroids plexus) are preserved.
- Brainstem auditory evoked response test is used to confirm the loss of cortical function but with preserved brainstem function.
