Case Vignettes in Neurology

PATIENT CASE STUDIES

Case 8 2/19 Patient
Case discussion This 76-year old female with a medical history of rheumatoid arthritis, peptic ulcer disease and hypothyroidism on replacement thyroid hormone presented with a two year’s history of progressive difficulty with walking. Her husband who accompanied her indicated a problem with balance with falls particularly at night when she awoke from bed to go to the bathroom. He had also noticed that over the same period she had difficulty with short term memory loss. She also complained of occasional electric shock sensations shooting from the neck down her back. On examination the BP was 145/85, pulse rate 80 and temperature 37C. General medical examination revealed vitiligo. There was no anemia, joint tenderness or swelling. She was alert, attentive, and oriented x 3. Recent memory was mildly impaired recalling 3 of 4 items at 5 minutes. Speech was fluent with good comprehension. Cranial nerves was noteworthy for mild bilateral pallor with enlargement of blind spots on confrontation. Motor examination revealed mild 4/5 weakness of hip flexion bilaterally but was otherwise normal. DTRs were 2+ in the upper extremities, 3+ at the knees and absent at the ankles. Plantar reflexes were bilaterally extensor. Sensory examination was abnormal and revealed moderate decrease in position sense and vibration sense in toes and ankles symmetrically. Pinprick and temperature were intact. Romberg was steady eyes open, unsteady eyes closed. Finger to nose testing was intact eyes open, and ataxic eyes closed.
Summarize the Case in 1-2 sentences. A 76 y/o female with a history of peptic ulcer disease presents with a 2 yr course of progressive difficulty walking, sensory ataxia, memory loss, and parathesia in the neck. Remarkable findings on examination are enlarged blind spots, proximal muscle weakness, absent Achilles reflex, bilateral Babinski, decreased proprioception and vibration sense, and unsteady Romberg with eyes closed. good; you left outhx of RA, hypothyroidism, Discuss lesion localization on the basis of the physical examination. The pathologic process is multifocal, involving the dorsal column of the spinal cord, upper motor neuron, peripheral nerves, and cortical area. good, you left out optic nerves Discuss underlying pathogenesis on the basis of clinical course. Her condition is chronic and progressive indicating a degenerative process (biochemical basis). good Indicate one likely clinical diagnosis. List (or classify) alternative diagnoses. Due to the central and peripheral neurological dysfunctions, a likely diagnosis is Vitamin B12 deficiency. Alternative diagnosis: Multiple sclerosis, neurosyphilis good Indicate 2 ancillary tests that would assist in confirming or refuting the clinical diagnosis. Indicate the test results that would confirm the clinical diagnosis. Serum levels of B12 can be evaluated and will be less than 100 pg/mL with Vit. B12 deficiency. Schillings Test detects intrinsic factor deficiency. It is wrong to say b12 has to be less than 100pg/ml for deficiency to be present; the assay for b12 is insensitive especially at low end of normal. a level below 300 pg/ml though still within the quote normal range may be indicative of deficiency in a patient who has signs suggestive of b12 deficiency. in these instances you are to obtain a test for evidence of deficiency i.e. plasma homocystein and serum methylmalonic acid. Indicate complications of the disease and ancillary tests that would help evaluate them. Megaloblastic anemia: bone marrow aspirate and peripheral smear DVT: Doppler Pancytopenia: CBC You need to include the neurological complications of b12 deficiency; ie. SACD( what is it?), peripheral neuropathy, dementia, psychosis, scotomas and blindness. I am not sure why you include dvt as a complication of b12 deficiency. Discuss how the underlying pathophysiology is relevant in the management of this patient. The underlying pathyphysiology circles around a decrease in vitamine B12 levels which impairs the function of methionine synthetase and methyl malonyl CoA mutase. This causes the production of abnormal fatty acids which alters the production of myelin. Treatment of B12 deficiency is to supply the missing vitamin early in the course of the disease to prevent further demyelination. On the terse side. what is the metabolic abnormality that causes the cns involvement and why? also important to talk about prevention, people with low normal b12 should receive replacement to prevent deficiency and complications also what are is the mechanism of production of b12 deficiency (remember that pathophysiology refers to the mechanisms of production of disease and its manifestations)

Case 8 2/19 Patient

Case discussion

This 76-year old female with a medical history of rheumatoid arthritis, peptic ulcer disease and hypothyroidism on replacement thyroid hormone presented with a two year’s history of progressive difficulty with walking. Her husband who accompanied her indicated a problem with balance with falls particularly at night when she awoke from bed to go to the bathroom. He had also noticed that over the same period she had difficulty with short term memory loss. She also complained of occasional electric shock sensations shooting from the neck down her back.

On examination the BP was 145/85, pulse rate 80 and temperature 37C. General medical examination revealed vitiligo. There was no anemia, joint tenderness or swelling. She was alert, attentive, and oriented x 3. Recent memory was mildly impaired recalling 3 of 4 items at 5 minutes. Speech was fluent with good comprehension. Cranial nerves was noteworthy for mild bilateral pallor with enlargement of blind spots on confrontation. Motor examination revealed mild 4/5 weakness of hip flexion bilaterally but was otherwise normal. DTRs were 2+ in the upper extremities, 3+ at the knees and absent at the ankles. Plantar reflexes were bilaterally extensor. Sensory examination was abnormal and revealed moderate decrease in position sense and vibration sense in toes and ankles symmetrically. Pinprick and temperature were intact. Romberg was steady eyes open, unsteady eyes closed. Finger to nose testing was intact eyes open, and ataxic eyes closed.

Summarize the Case in 1-2 sentences.

A 76 y/o female with a history of peptic ulcer disease presents with a 2 yr course of progressive difficulty walking, sensory ataxia, memory loss, and parathesia in the neck. Remarkable findings on examination are enlarged blind spots, proximal muscle weakness, absent Achilles reflex, bilateral Babinski, decreased proprioception and vibration sense, and unsteady Romberg with eyes closed.

good; you left outhx of RA, hypothyroidism,

Discuss lesion localization on the basis of the physical examination.

The pathologic process is multifocal, involving the dorsal column of the spinal cord, upper motor neuron, peripheral nerves, and cortical area.

good, you left out optic nerves

Discuss underlying pathogenesis on the basis of clinical course.

Her condition is chronic and progressive indicating a degenerative process (biochemical basis).

good

Indicate one likely clinical diagnosis. List (or classify) alternative diagnoses.

Due to the central and peripheral neurological dysfunctions, a likely diagnosis is Vitamin B12 deficiency. Alternative diagnosis: Multiple sclerosis, neurosyphilis

good

Indicate 2 ancillary tests that would assist in confirming or refuting the clinical diagnosis. Indicate the test results that would confirm the clinical diagnosis.

Serum levels of B12 can be evaluated and will be less than 100 pg/mL with Vit. B12 deficiency. Schillings Test detects intrinsic factor deficiency.

It is wrong to say b12 has to be less than 100pg/ml for deficiency to be present; the assay for b12 is insensitive especially at low end of normal. a level below 300 pg/ml though still within the quote normal range may be indicative of deficiency in a patient who has signs suggestive of b12 deficiency. in these instances you are to obtain a test for evidence of deficiency i.e. plasma homocystein and serum methylmalonic acid.

Indicate complications of the disease and ancillary tests that would help evaluate them.

Megaloblastic anemia: bone marrow aspirate and peripheral smear
DVT: Doppler
Pancytopenia: CBC

You need to include the neurological complications of b12 deficiency; ie. SACD( what is it?), peripheral neuropathy, dementia, psychosis, scotomas and blindness.
I am not sure why you include dvt as a complication of b12 deficiency.

Discuss how the underlying pathophysiology is relevant in the management of this patient.

The underlying pathyphysiology circles around a decrease in vitamine B12 levels which impairs the function of methionine synthetase and methyl malonyl CoA mutase. This causes the production of abnormal fatty acids which alters the production of myelin. Treatment of B12 deficiency is to supply the missing vitamin early in the course of the disease to prevent further demyelination.

On the terse side. what is the metabolic abnormality that causes the cns involvement and why? also important to talk about prevention, people with low normal b12 should receive replacement to prevent deficiency and complications also what are is the mechanism of production of b12 deficiency (remember that pathophysiology refers to the mechanisms of production of disease and its manifestations)