NEURO Flashcards
Subacute combined degeneration
Severe and prolonged vitamin B12 deficiency can result in subacute combined degeneration, which refers to a dysfunction of the corticospinal and dorsal sensory tracts of the spinal cord that manifests as spastic paresis with reduced vibration and position sense and ataxia.
MRI can show increased signal in the affected white-matter pathways without associated inflammatory changes. Laboratory study results show a low serum vitamin B12 level with elevated levels of serum methylmalonic acid and homocysteine. Macrocytic anemia may be present, but the neurologic manifestations of B12 deficiency may precede development of anemia.
Copper deficiency (due to malabsorption, nutritional deficiency, or zinc toxicity) can also cause subacute combined degeneration. This entity should be considered in patients with suggestive symptoms who have normal vitamin B12 levels.
Myelopathy from such nutritional deficiencies should specifically be considered in patients with previous bariatric surgical procedures.
Restless Legs Syndrome
worse at rest and at night and is transiently relieved by movement. RLS can interfere with falling or staying asleep. Patients with RLS should be screened for iron deficiency because iron supplementation in the presence of low-normal ferritin levels (15-75 ng/mL [15-75 μg/L]) may resolve the symptoms. Supplementation with intravenous ferric carboxymaltose is likely efficacious in idiopathic RLS, whereas efficacy of oral iron supplementation remains unproven. Other risk factors for RLS include uremia, sleep apnea, pregnancy, and certain medications (including selective serotonin reuptake inhibitors, antipsychotic agents, and stimulant drugs).
Restless Legs Syndrome Tx
First-line pharmacologic treatments include the dopamine agonists pramipexole, ropinirole, and rotigotine. Additional options include levodopa, pergolide, gabapentin, gabapentin enacarbil, pregabalin, and opioid agonists (such as prolonged-release oxycodone-naloxone and methadone). Chronic use of dopamine agonists, however effective, may lead to either augmentation (that is, symptoms start earlier in the day) or rebound (that is, symptoms return with greater severity after the medication wears off).
tension-type headache.
Acetaminophen, aspirin, NSAIDs, caffeine-containing compounds, and amitriptyline are effective acute and preventive treatments for tension-type headache, but muscle relaxants, benzodiazepines, opioids, and onabotulinum toxin A have no role in the management of tension-type headache.
Infarction of the spinal cord
Acute onset of flaccid paralysis or weakness and pinprick sensation loss below the level of the infarction
Potential causes include emboli, hypotension during cardiovascular/aortic surgery, and AV malformations
ALS Symptoms?
Upper motoneuron signs (e.g., hyperreflexia, spasticity, and extensor plantar response) coexistent with lower motoneuron findings (e.g., atrophy and fasciculation). Sensory deficits are characteristically absent.
Muscle weakness in patients with ALS usually begins distally and asymmetrically, although 20% of patients have bulbar-onset ALS with difficulty speaking and swallowing. Alternative diagnoses also must be excluded by brain and cervical spinal imaging and laboratory testing; cervical cord compression, vitamin B12 and copper deficiencies, Lyme disease, hyperparathyroidism, and thyrotoxicosis must be excluded. Spirometry and overnight pulse oximetry studies can establish the presence of respiratory insufficiency. Patients with bulbar signs or symptoms require evaluation of swallowing function.
Diagnosis is based on clinical evidence of both upper and lower motor neuron signs on examination and EMG evidence of lower motor neuron signs in at least two (probable ALS) or more (definite ALS) regions.
What is not present in ALS?
Findings not typical for ALS include predominant sensory symptoms or pain, early cognitive impairment, and ocular muscle weakness.
Fasciculations in the absence of associated muscle atrophy or weakness are not caused by ALS.
Weakness in the absence of fasciculations is not a result of ALS.
Riluzole and edaravone may modestly increase survival, and sodium phenylbutyrate–taurursodiol may improve outcomes other than mortality.
Begin noninvasive ventilatory support for patients with respiratory insufficiency. Placement of a percutaneous endoscopic gastrostomy tube is indicated when weight loss or swallowing difficulty occurs.
GBS Differential?
The differential diagnosis of GBS includes botulism (descending weakness), myasthenic crisis (without pain and paresthesia), acute myelopathies (hyperreflexia and upper motor neuron signs), West Nile virus infection (asymmetric paralysis, fever, and muscle pain), carcinomatous and sarcoid meningitis (slower course), Lyme disease, HIV seroconversion, porphyria, and tick paralysis.
GBS tx?
CSF analysis shows a pattern of a highly elevated protein level with a normal or mildly elevated leukocyte count (albuminocytologic dissociation) in 90% of patients. Early normal CSF does not rule out GBS. EMG is the confirmatory test and shows a predominantly demyelinating pattern; sensitivity is initially low but 90% by week 5. Initiation of treatment should not await EMG confirmation; a negative early study should be repeated later if the diagnosis remains suspected. Additional studies, such as spinal MRI and serologic testing for Lyme disease, HIV, and myasthenia antibodies, may be considered in appropriate clinical settings.
Therapy includes supportive management and immunotherapy.
GBS intubation & Steriods?
Decisions about intubation, which should be guided by the need for airway protection and measurement of forced vital capacity and negative inspiratory force, should be made before emergence of hypoxemia. Both plasmapheresis and intravenous immune globulin (IVIG) have equal efficacy in shortening the time to recovery and the duration of ventilation. Serial treatment with IVIG after plasma exchange is not superior to either treatment alone and has not shown significant added benefit.
Glucocorticoids are contraindicated in GBS and may worsen outcome.
Parinaud syndrome?
Pineal tumor: loss of pupillary reaction, vertical gaze paralysis (cannot look up), the loss of optokinetic nystagmus, and ataxia. Some pineal tumors are germinomas that can secrete HCG.
When not to give steroids for neuro?
If spinal abscess
Tx for ALS?
Riluzole is a glutamate inhibitor
Meralgia paresthetica?
Compression of lateral femoral cutaneous nerve at the inguinal ligament. Pain, paresthesia, and numbness in the anterolateral thigh without any muscle weakness or abnormalities of the deep tendon reflexes.
Diagnosed clinically. Management includes reassurance and reduction of exacerbating factors (eg, avoidance of tight-fitting garments, weight loss).
Frontotemporal dementia (FTD)?
Personality and behavior changes such as disinhibition, apathy, loss of empathy, ritualistic behavior, hyperorality, and/or executive function decline. Some patients with FTD develop motor neuron disease.
Tx of Dementia?
Acetylcholinesterase inhibitors are first-line pharmacotherapy for cognitive symptoms associated with dementia.
Memantine, an NMDA receptor antagonist, may also be beneficial for patients with dementia.
Stroke in young pt?
Young and without traditional cardiovascular disease risk factors, particularly those with risk factors for unusual infections. Meningovascular syphilis can present with stroke due to intracranial arteritis. The diagnosis can be confirmed with cerebrospinal fluid Venereal Disease Research Laboratory (VDRL) testing; penicillin is the appropriate treatment.
Acoustic neuromas?
proliferation of Schwann cells (schwannomas).
Amaurosis fugax?
Sudden and transient monocular blindness. Even though it is reversible, it is a marker of carotid artery atherosclerotic disease that is usually advanced. Physical examination will often reveal acarotid bruit. Carotid Doppler evaluation is necessary to evaluate the extent of the disease and toassess the need fora carotid endarterectomy.
Brain death?
Absence of reflexes associated with cortical and brainstem function (pupillary, oculocephalic, oculovestibular [caloric], corneal, gag, sucking, swallowing, and extensor posturing).
Patients with brain death can have reflexes and movements, but these originate from peripheral nerves or the spinal cord.
Post-partum Bells palsy?
peripheral neuropathy involving the facial nerve (CN VII), acute, progressive, unilateral weakness. It should be treated with glucocorticoids with or without acyclovir, and patients have an excellent prognosis for full recovery over weeks to a few months.
carotid artery dissection
A unilateral headache with partial Horner syndrome should be considered a carotid artery dissection until proven otherwise. Head and neck vasculature imaging (eg, CT angiography) is the initial diagnostic modality of choice.
cremasteric reflex?
The cremasteric reflex is regulated at the L1-L2 level of the spinal cord. This reflex can be diminished or lost secondary to diabetic autonomic neuropathy.
Vagus nerve?
Parasympathetic innervation to the esophagus and stomach comes from the vagus nerve (CN X), which originates in the medulla, and primarily promotes motility.
Parasympathetic underactivity would slow peristalsis and could cause dysphagia and/or gastroparesis
