Case 27

Published on 03/03/2015 by admin

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Last modified 03/03/2015

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Case 27

HISTORY AND PHYSICAL EXAMINATION

A 45-year-old woman developed increasing abdominal pain, nausea, and occasional vomiting. She underwent a cholecystectomy at a community hospital with no help. Pain persisted and she had increasing weight loss. Upper endoscopy was normal and laparoscopy showed minor adhesions. She then developed abdominal distention and an ileus. An exploratory laparotomy revealed a small bowel perforation and a 15 cm of small bowel was resected with primary anastomosis. Her postoperative course was complicated by fever, prolonged ileus, and abdominal infection. She required mechanical ventilation for about 3 days for sepsis and respiratory failure. She was hospitalized for a total of 10 weeks and was started on intravenous total protein nutrition due to malnutrition and severe loss of weight.

During this prolonged hospitalization, she reported rapidly progressive weakness of the right hand which became complete over one to two weeks. She was ill and obtunded and could not give better details about her leg symptoms. Severe distal weakness of both lower extremities, worse on the right was noted by treating physicians during her hospitalization, requiring bilateral ankle braces. She was diagnosed with a secondary critical illness polyneuropathy and was discharged to rehabilitation. However, she was readmitted two weeks later to our teaching hospital because of nausea and persistent abdominal pain. Upon arrival, she reported that she had developed, while in rehabilitation, abrupt weakness of the left hand, particularly the left thumb and index and middle fingers.

Her past medical history was relevant for diffuse joint pain and swelling, six months prior to the initial presentation, diagnosed as “arthritis” and treated successfully with oral prednisone for 3 months. She has not had any skin rash. The patient was receiving intravenous total protein nutrition.

On examination, she was cachectic and ill appearing woman with modest abdominal pain. She was afebrile with a blood pressure of 160/70. General physical examination was relevant for distended and moderately tender abdomen with no guarding or rebound tenderness. Bowel sounds were hypoactive. The neurological examination revealed normal mental status and cranial nerves. The motor examination revealed significant atrophy in both lower extremities below the knees, as well as the right hand and forearm and the left thenar muscles. There were no fasciculations. Muscle strength testing revealed asymmetrical weakness most notable in the upper extremities. Detailed manual muscle testing was as follows (Modified Medical Research Council [MRC] scale):

	Right	Left
Shoulder abduction	5/5	5/5
Elbow flexion	5/5	5/5
Elbow extension	2/5	5/5
Pronation	0/5	2/5
Finger flexion (digits 1, 2, and 3)	0/5	0/5
Finger flexion (digits 4 and 5)	0/5	4+/5
Wrist flexion	0/5	2/5
Wrist extension	0/5	5/5
Finger extension	0/5	4+/5
Finger abduction	0/5	4+/5
	Right	Left
Hip flexion	5/5	5/5
Hip extension	5/5	5/5
Knee extension	4+/5	4+/5
Knee flexion	4+/5	4+/5
Foot dorsiflexion	0/5	4−/5
Toe dorsiflexion	0/5	0/5
Plantar flexion	0/5	4/5
Ankle inversion	0/5	0/5
Ankle eversion	0/5	0/5

Sensation revealed a stocking glove distribution bilaterally with no clear asymmetry. There was no clear sensory loss in the left median distribution compared to the ulnar distribution on formal testing. The deep tendon reflexes were +2 at the biceps bilaterally, +2 at the left triceps, and absent at the right triceps, and absent at the brachioradialis bilaterally. The knee jerks were +1 bilaterally, while the ankle jerks were absent. Plantar responses are both flexors. Gait was not examined.

The laboratory studies revealed a white cell count of 11 000 cm³ with no bands. Westegren sedimentation rate and C-reactive protein were elevated at 75 mm/h and 12.50, respectively. Liver function tests revealed elevated AST, ALT, and alkaline phosphatase at 84 U/L, 61 U/L, and 429 U/L, respectively. Prothrombin time and INR were slightly elevated at 12.8 and 1.3, respectively. Antinuclear antibody (ANA) and antineruonal cytoplasmic antibodies (ANCA) were negative. Hepatitis B and B core antigens were reactive. Hepatitis B and core antibodies were nonreactive. Viral DNA count was more than 8.3 millions copies. Hepatitis A and C antibodies were nonreactive. Cryoglobulins were negative. Endomysial antibody was negative. Vitamin B12 and E were normal at 662 pg/mL and 15 mg/L, respectively. Abdominal x-rays revealed dilated small bowel loops with air-fluid level. An electrodiagnostic (EDX) study was requested.

Please now review the Nerve Conduction Studies and Needle EMG tables.

EDX FINDINGS AND INTERPRETATION OF DATA

The relevant EDX findings in this case include:

1. Absent routine sensory nerve action potentials (SNAPs) and routine compound muscle action potentials (CMAPs) in both lower extremities. This finding is consistent with a generalized axon-loss disorder affecting the sensory and motor fibers, such as a sensorimotor peripheral polyneuropathy.

2. Asymmetrical peroneal motor nerve conduction studies (NCSs), recording tibialis anterior, in the lower extremities. The responses were absent on the right while they were evoked with low CMAP amplitudes on the left with no conduction block or slowing of distal latency and minimal slowing of conduction velocity. This finding suggests that the disorder is asymmetrical.

3. Absent routine sensory and motor conduction studies in the right upper extremity while the left upper extremity showed absent median sensory and motor conduction studies and only borderline or slightly reduced ulnar and radial SNAP amplitudes and ulnar motor CMAP amplitude with normal distal latency, conduction velocity and F wave minimal latency. This is a very useful finding; it points to a severe left median mononeuropathy as well as an asymmetrical polyneuropathy in the upper extremities. The left median mononeuropathy could not be localized since the median motor and sensory responses were absent. Hence, a remote left carpal tunnel cannot be excluded at this point.

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