Case History #77
Date of Consultation: 8-4-1988
HISTORY OF PRESENT ILLNESS:
This 28-year-old left-handed white female paralegal worker was referred for neurologic evaluation because of right lower limb weakness. In 1977, the patient noted numbness and tingling in the sole of the right foot. As time passed, she noted that these sensory symptoms intensified and seemed to progress, in that they moved up the posterior aspect of the right calf. She also noted weakness of the right foot and ankle, especially when attempting to point her toes or turn her foot inward. A deformity of the right foot developed in the form of a high arch and a tendency for her toes to hyperextend at the metatarsophalangeal joints and flex at the interphalangeal joints (hammer toes). All of these symptoms progressed slowly for a few years but then remained stable for perhaps the 3 to 4 years prior to consultation.
NEUROLOGICAL EXAMINATION:
Mental Status Exam: Intact.
Cranial Nerves: Intact.
Motor System: Atrophy of the calf muscles and intrinsic foot muscles was present in the right lower limb. The circumference of the leg 8 cm below the tip of the patella was 33 cm on the right and 36 cm on the left. Muscle tone was normal in all 4 limbs. Muscle power was normal in both upper limbs and in the left lower limb. In the right lower limb, plantar flexion of the ankle, inversion of the foot, and flexion of the toes were moderately weak (4/5). Ankle dorsiflexion, eversion of the foot, and extension of the toes were normal (5/5), as were all other movements of the right lower limb.
Reflexes: Deep tendon reflexes were normal (2/4) and symmetric, except for an absent right ankle jerk. Plantar reflexes were flexor bilaterally.
Sensory System: Sensory examination was normal, except in the right lower limb. In the right lower limb, there was decreased appreciation of pinprick and light touch involving the entire sole of the foot. There was an inconsistent decreased appreciation of these sensations up the posterior aspect of the right calf. In addition, stimulation of the sole of the foot elicited an uncomfortable tingling and burning sensation (hyperpathia).
Cerebellar Function: Intact.
Gait and Stance: Regular gait was performed normally, except for limping on the right lower limb and instability of the right ankle. Tandem gait was performed normally, except for difficulty in stabilizing the right ankle in the support phase. The patient was able to walk on her heels without difficulty. However, she was unable to walk on her toes on the right. The Romberg test was negative.
Questions
1. Does this patient's weakness suggest an upper motor neuron or lower motor neuron process?
2. Is there evidence of spinal cord involvement in this case and, if so, at what level?
3. Is there evidence of dorsal or ventral root involvement or spinal nerve involvement in this case, and, if so, what is the level(s) of the involvement?
4. Is there evidence of plexus or peripheral nerve involvement in this case? If so, indicate the specific structure(s) involved by the pathologic process.
5. Where is the anatomical location of the pathologic process leading to this patient’s condition?
6. In general, what type of pathological process do you think is involved in this case?
7. What diagnostic procedure(s) would you undertake at this point?
