Chapter 1. Diagnosis of Neurological Disease

Question 1

Question 1-1: Which of the following historical findings would argue against a spinal cause for paraparesis?

A. Urinary incontinence

B. Headache

C. Sudden onset

D. Absence of back pain

Answer 1

(B) Headache would suggest a cerebral cause for paraparesis. such as puasagittal meningioma. Urinary incontinence can occur in spinal or cerebral causes of paraparesis. Sudden onset of paraparesis would suggest a spinal cause, although bilateral frontal infarctions due to occlusion of a common anterior cerebral artery could produce this as well Back pain is present in most structural spinal causes of paraparesis, but some spinal pathologies may also be painless. such as transverse myelitis, infarction, or vitamin B12 deficiency. (P5)

Question 2

Question 1-2: Sarcoidosis may cause which of the following? A. Bell’s palsy B. Diabetes insipidus C. Ophthalmoplegia D. Peripheral neuropathy E. All of the above

Answer 2

(E) Answer 1-2: E. Sarcoidosis can produce any of these manifestations, although not all will be found in all patients, especially at the same stage in the disease process. (p6)

Question 3

Question 1-3: Occam’s razor, a basic logical precept, when applied to central nervous system localization, states that multiple signs are more likely to be due to a single lesion than multiple lesions. Which of the following disorders seem to contradict this when considering cerebral localization? A. ALS B. Vasculitis C. Cardiogenic emboli D. Multiple sclerosis E. None ofthese

Answer 3

(E) Answer 1-3: E. Occam’s razor is a commonly used tool in neurologic localization which helps us to usually reach the correct diagnosis by explaining the patient’s presentation by a single entity. All of the listed conditions produce deficits which could nol be explained by a single anatomic lesion, yet each is due to a single disease process. Simultaneous upper and lower motor neuron signs have a very limited differential with ALS predominant. Vasculitis and cardiogenic emboli produce multifocal infarctions in the brain which prompt search for these two conditions. Multiple sclerosis is the prototypic condition of mUltiple lesions in time and space, but this pattern, by itself, raises concern over MS. (P8)

Question 4

Question 1-4: Numbness and burning of the feet. A. Multiple sclerosis B. Sarcoidosis C. Peripheral neuropathy D. ALS E. Acoustic neuroma

Answer 4

(C) Answer 1-4: C. Peripheral neuropathy is the most common cause of burning and numbness of the feet. Cauda equina syndrome is among the spinal causes of the same symptoms, although other symptoms are expected. (P5)

Question 5

Question 1-5: Multiple episodes of numbness or weakness or visual loss over years, with a duration ofdays to weeks. A. Multiple sclerosis B. Sarcoidosis C. Peripheral neuropathy D. ALS E. Acoustic neuroma

Answer 5

(A) Answer 1-5: A. MS is a common cause of relapsing-remitting neurologic symptoms and signs. Other potential causes would be vasculitis, but this is much less common. (P5)

Question 6

Question 1-6: Weak on one side and unable to hear from one ear. A. Multiple sclerosis B. Sarcoidosis C. Peripheral neuropathy D. ALS E. Acoustic neuroma

Answer 6

(E) Answer 1-6: E. Acoustic neuroma at the cerebello-pontine angle typically causes ipsilateral deafness from damage to the acoustic nerve. Ipsilateral ataxia can be cal!Sed by cerebellar involvement of the lwuor. Contralalt:ral hemiparesis can be caused by compression of the pontine portion of the corticospinal tract. (P5)

Question 7

Question 1-7: The complaint of”blackout” refers to which elemental symptom? A. Loss of vision B. Confusion C. Loss of consciousness D. Memory lapse E. Any of the above

Answer 7

(E) Answer 1-7: E. “Blackout” is a very nonspecific teno, like dizziness. While we may assume that the patient means loss of consciousness, there are other symptoms which rnay be considered to be blackouts, from cognitive disturbance (intermittent confusion or mernory lapse), or loss of vision. Misinterpretation of a term is just as likely when the patient uses a medical term - we need to ensure that what the patient means by “blackout,” “dizziness,” “seizure,” or “stroke” is fully understood. (P5)

Question 8

Question 1-8: Which is the least important aspect of the screening neurologic examination? A. Visual fields B. Tendon reflexes C. Olfaction D. Muscle strength E. Sensation to pin prick

Answer 8

(C) Answer 1-8: C. Olfaction is rarely tested for during the screening neurologic examination because most common neurologic conditions do not alter this cranial nerve function and there are non-neurologic causes of deficit. Also, most patients with absent or defective olfaction have the defect on the basis of nasal disease rather than an olfactory groove meningioma or other lesion in this location. Olfaction should be tested as part of the comprehensive neurologic examination and when examining patients especially with dementia associated with affective disturbance and in patients who have had recent head injury. In reality, almost all of these patients will have brain CT or MRI so the diagnostic utility of this examination rmding is limited. The other listed examination components are integral to the screening examination. Ofthese, visual fields are the most likely to be overlooked, missing a hemianopsia when no other hard localizing finding may exist. (P7)

Question 9

Question 1-9: Gastric bypass surgery can produce neurologic disturbance by virtue of which of the following disorders? A. Vitamin BI2 deficiency B. Thiamine deficiency c. Vitamin E deficiency D. Riboflavin deficiency

Answer 9

Answer 1-9: A. Vitamin BI2 deficiency is commonly due to gastric surgery, with impaired absorption of the vitamin. Deficiencies of the other listed vitamins are not typical of gastric bypass surgery. (P6)