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A 69-year-old woman presents to the clinic with memory difficulty. The patient’s daughter is concerned because she is having difficulty doing her finances, such as paying bills. Memory impairment testing reveals the poor ability to generate lists of words or copy diagrams (intersecting pentagons). Her remaining physical examination is normal. Which of the following anatomic findings is most likely with her condition?
Alzheimer’s disease can be quite diffuse, but there is particular involvement of the medial temporal lobes and cortical association areas. The atrophy of the hippocampus is particularly marked. Microscopic examination reveals neurofibrillary tangles and amyloid plaques.
A 38-year-old man presents with involuntary facial grimacing, shrugging of the shoulders, and jerking movements of the limb. His father was similarly affected. There is also a history of mood changes for the past 3 months. On examination, he appears restless with intermittent slow movements of his hands and face. He has difficulty performing rapid finger movements, and tone is decreased in the upper and lower limbs. Which of the following is most likely to represent the progression of his illness?
This is a case of Huntington’s chorea. It is an autosomal dominant gene (found on the short arm of chromosome 4), and male and female children are equally affected. Movement disorder, mental deterioration, and personality change are the hallmarks of the disease, but can be very subtle initially. The disease starts typically between ages 35 and 40 (although the variation is wide) and runs its course in about 15 years. The akinetic rigid variety (Westphal variant) of Huntington’s typically has a childhood onset.
An 18-year-old woman has periodic episodes that begin with severely decreased vision, followed by ataxia, dysarthria, and tinnitus. The symptoms last for 30 minutes and are then followed by a throbbing occipital headache. Which of the following is the most likely diagnosis?
Basilar migraine can be very dramatic, and can resemble ischemia in the territory of the basilar posterior cerebral arteries. The visual symptoms of basilar migraine typically affect the whole of both visual fields, and can even cause temporary cortical blindness. There can also be an alarming period of coma or quadriplegia.
A 6-month-old child presents with recurrent seizures and poor development. The evaluation reveals a baby with hydrocephalus, impaired movement of the extremities, hypotonia, and retinal abnormalities. A computerized tomography (CT) scan demonstrates large ventricles and calcified lesions. Which of the following is the most likely diagnosis?
Toxoplasmosis is the most likely diagnosis. The infection has a predilection for the CNS and the eye, and produces encephalitis in utero. Symptoms can be evident in the first few days of life. Infants born with active disease may have fever, rash, seizures, and hepatosplenomegaly at birth.
A74-year-old woman develops acute neurologic symptoms and presents to the emergency room. An urgent magnetic resonance imaging (MRI) scan demonstrates acute occlusion in the right posterior cerebral artery. Which of the following clinical symptoms is she most likely to have?
Occlusion of the right posterior cerebral artery is most likely to cause homonymous hemianopia. This artery conveys blood to the inferior and medial portion of the posterior temporal and occipital lobes and to the optic thalamus.
A 53-year-old man complains of clumsiness with both hands, like having difficulty doing up buttons or using his keys. Physical examination reveals fasciculations of his thigh and forearm muscles; diffuse muscle weakness, loss of muscle bulk, and increased tone in the upper and lower limbs. There is generalized hyperreflexia, and positive Babinski signs bilaterally. Which of the following is the most likely natural progression of this condition?
This man has amyotrophic lateral sclerosis (ALS). The disease causes neuronal loss in the anterior horns of the spinal cord and motor nuclei of the lower brain stem. The disease is one of constant progression, rather than remissions and exacerbations, and death usually occurs within 5 years. There is no sensory loss and no seizure diathesis, because only the motor system is involved. There can be signs of hyperreflexia and spasticity, depending on the balance of upper and lower motor neuron damage, but not cogwheel rigidity.
A 38-year-old man presents with involuntary facial grimacing, shrugging of the shoulders, and jerking movements of the limb. His father was similarly affected. There is also a history of mood changes for the past 3 months. On examination, he appears restless with intermittent slow movements of his hands and face. He has difficulty performing rapid finger movements, and tone is decreased in the upper and lower limbs. Which of the following treatments is helpful in suppressing the movements?
There are disturbances of norepinephrine, glutamic acid decarboxylase, choline acetyltransferase, GABA, acetylcholine, and somatostatin, but their significance is poorly understood. Dopamine blocking agents (e.g., haloperidol) can be used to treat psychosis and ameliorate chorea but do not alter the course of disease. Presynaptic dopamine depletors such as clozapine, reserpine, or tetrabenazine can be used for chorea as well, but have significant side effects. Antidepressants are helpful for symptomatic treatment. Most patients eventually end up in an institution.
A 22-year-old woman presents with acute vision loss and pain in the left eye, but no other symptoms. On examination she appears well, visual acuity is not possible, and she can only perceive movement and bright light. The direct papillary reflex is absent but the indirect (consensual) response is normal. The optic disc is edematous. Which of the following symptoms is also most likely present in patients with this condition?
This patient has multiple sclerosis (MS). Weakness or numbness in one or more limbs is the initial manifestation of disease in about half the patients. Other common initial presentations include optic neuritis (25%) and acute myelitis. Hemiplegia, seizures, and cervical myelopathy (in older patients) occur occasionally as the initial manifestation. Sphincter impairment usually occurs later in the disease.
A 63-year-old man developed a transient episode of vertigo, slurred speech, diplopia, and paresthesias. He is symptom-free now, and clinical examination is entirely normal. His past medical history is significant for hypertension and dyslipidemia. Which of the following is the most likely cause for symptoms?
Posterior circulation TIA is suggested by the transient episodes. The basilar artery is formed by the two vertebral arteries and supplies the pons, the midbrain, and the cerebellum. With vertebrobasilar TIAs, tinnitus, vertigo, diplopia, ataxia, hemiparesis, and bilateral visual impairment are common findings.
A 75-year-old woman presents with symptoms of visual change and facial weakness. On examination, the pupils are equal and reactive to light, the fundi appear normal, and there is a right homonymous visual field defect. Which of the following is the most likely cause of the right homonymous hemianopia?
The hemianopia is due to a lesion of the left optic radiations. The posterior cerebral artery arises from the basilar artery but is sometimes a branch of the internal carotid. With posterior cerebral artery lesions affecting the occipital cortex, it is possible for the hemianopia to be an isolated finding.
A 10-year-old boy has multiple tan-colored patches on his skin, and freckle-like skin changes in his armpit area. The rest of clinical examination is normal. Which of the following conditions is also found in patients with this disorder as they get older?
The two common forms of neurofibromatosis (NF-1 and NF-2) are genetically distinct. NF-1 is the type with multiple café au lait spots and is associated with axillary or inguinal freckling, iris hamartomas (Lisch nodules), peripheral neurofibromas, and bony abnormalities (including kyphoscoliosis). NF-2 is associated with CNS tumors, particularly bilateral eighth nerve tumors. Skin lesions are spare or absent, and early lens opacities can occur.
A 44-year-old man presents with involuntary movements of his face, shoulders, and arms. His father had a similar condition. There is also a history of mood changes for the past 6 months. On examination, he appears restless with intermittent slow movements of his hands and face. He has difficulty performing rapid finger movements, and tone is decreased in the upper and lower limbs. Which of the following is the most likely diagnosis?
Huntington’s chorea is the most likely diagnosis given the hereditary nature of this patient’s illness (autosomal dominants). It differs from Sydenham’s chorea by its gradual onset and slow choreic movements versus brusque jerks seen in Sydenham’s. The caudate nucleus and putamen are both severely involved in Huntington’s chorea, and degeneration of the caudate nucleus results in enlarged lateral ventricles (with a “butterfly” appearance on CT). Atrophy is very widespread in the brain and includes the cerebral cortex. A decrease in glucose metabolism as revealed on positron emission tomography (PET) scan precedes the evidence of tissue loss.
A 56-year-old man is brought to the emergency department by his wife because of memory loss and difficulty walking. She has noticed personality changes, truancy from work, and lack of personal care over the past 1 year. On examination he appears unkempt, smells of urine, and is uncooperative. He cannot recall the date or season, and gets angry when asked questions. His answers are often fabricated when checked with his wife. The blood pressure is 150/90 mm Hg, pulse 100/min, and he is diaphoretic and tremulous. His gait is wide based, and motor strength and reflexes are normal. His ocular movements are normal but there is nystagmus on lateral gaze. In the past he has had multiple admissions for alcohol withdrawal. Which of the following is the most appropriate next step in management?
Prophylactic administration of diazepam in a withdrawing alcoholic can prevent or reduce severe syndromes such as delirium tremens (DTs). Prophylactic phenytoin, however, is not helpful. A calm, quiet environment with close observation and frequent reassurance is very important. Vitamin administration (especially thiamine) is important, but frequently, severe magnesium depletion slows improvement.
A 60-year-old man with diabetes acutely develops double vision and discomfort in his left eye. On examination, there is ptosis of the left eyelid, the eye is rotated down and out, and the pupil is 3 mm and reactive to light. The right eye is normal. Which of the following is the most likely diagnosis?
Third nerve palsy can result in ptosis of the eyelid. There is also loss of the ability to open the eye, and the eyeball is deviated outward and slightly downward. With complete lesions, the pupil is dilated, does not react to light, and loses the power of accommodation. In diabetes, the pupil is often spared. The sixth cranial nerve can also be affected by diabetes, but this is much less common.
A 48-year-old man complains of recurrent episodes of sudden-onset dizziness. He notices an abrupt onset of a spinning sensation when sitting up or lying down in bed. The symptoms last for 30 seconds and then resolve completely. He has no hearing change or other neurologic symptoms, and his physical examination is completely normal. A Dix-Hallpike maneuver reproduces his symptoms. Which of the following is the most likely mechanism for his vertigo symptoms?
This person has benign paroxysmal positional vertigo (BPPV), which is characterized by sudden-onset brief episodes of vertigo lasting less than a minute. The symptoms are usually brought on by head movement. The cause is commonly attributed to calcium debris in the semicircular canals, known as canalithiasis. The debris is loose otoconia (calcium carbonate) within the utricular sac. Although BPPV can occur after head trauma, there is usually no obvious precipitating factor. It generally abates spontaneously and can be treated with vestibular rehabilitation.
A 40-year-old man is injured in a car accident and fractures his left elbow. He now complains of numbness of his fourth and fifth fingers, and weakness in his hand grip. Neurologic findings confirm weakness of handgrip with weakness of finger abduction and adduction, and decreased sensation over the fifth finger and lateral aspect of fourth finger. Which of the following is the most likely diagnosis?
Injury to the ulnar nerve results in impaired adduction and abduction of the fingers. The nerve is commonly injured in elbow dislocations and fractures. The fibers arise from the eighth cervical and the first thoracic segments. The ulnar is a mixed nerve with sensory supply to the medial hand.
A 31-year-old woman complains of excessive sleepiness during the daytime for years despite adequate nighttime sleep. She has episodes of intense drowsiness three to four times a day, even when at work or while eating meals. She has sought medical attention in the past, after falling asleep while driving. She is slender and otherwise healthy and on no medications. Which of the following treatments is most likely indicated for her condition?
This woman does not have risk factors for sleep apnea (older age, snoring, obesity) and likely has narcolepsy. Adrenergic stimulant drugs such as methylphenidate or amphetamines help the sleepiness, and tricyclic compounds can help the cataplexy. Strategically planned naps can also be helpful.
A 43-year-old man is referred from the emergency department with memory loss and difficulty walking. He was brought in by his wife who has noticed personality changes, truancy from work, and lack of personal care over the past 2 years. On examination he appears unkempt, smells of urine, and is uncooperative. He cannot recall the date or season, and gets angry when asked questions. His answers are often fabricated when checked with his wife. His gait is wide-based, and there is loss of sensation in his feet up to the shins. His motor strength and reflexes are normal. His ocular movements are normal and there is no nystagmus. In the past he has had multiple admissions for alcohol withdrawal. Which of the following is the most likely diagnosis?
The combination of symptoms is typical of chronic alcohol abuse. The mental symptoms are suggestive of Wernicke-Korsakoff syndrome. A distal limb sensory-motor neuropathy is also typical of alcoholism. Confusion, tremulousness, and disorientation are typical for acute alcohol intoxication. Wernicke’s encephalopathy is a symptom complex of ophthalmoplegia, ataxia, nystagmus, and acute confusional state.
A 59-year-old woman has numbness and tingling in her feet. On examination, there are signs of involvement of the peripheral nerves in the form of decreased sensation, motor weakness, and distal reflex loss. The findings are symmetric. Which of the following medical conditions is most likely to explain her peripheral nerve findings?
These signs and symptoms develop in a fairly large percentage of patients with diabetes mellitus. Loss of proprioceptive sensation together with absent reflexes superficially resembles tabes dorsalis. If sensory loss is severe, Charcot’s joints can develop.
A 94-year-old man presents with progressive headaches, light-headedness, drowsiness, and unsteady gait over 6 weeks. On examination, his blood pressure is 160/90 mm Hg, pulse 70/min, lungs clear, and he has no focal weakness. His gait is unsteady but sensation in the feet is normal. A CT scan reveals a hyperintense clot over the left cerebral cortex. Which of the following is the most likely cause for this clot?
A subdural hematoma is almost always of venous origin and secondary to a minor or severe injury to the head, but may occur in blood dyscrasias or cachexia in the absence of trauma. Acute subdural hematomas commonly present with a fluctuating level of consciousness and significant cerebral damage. Chronic subdurals may also present with seizures or papilledema.