A case of intramedullary neurinoma.

Case Report K., a 35-year-old farmer (N.S. 350), was admitted to the Neurosurgical Unit, Government General Hospital, Madras, India, in 1951, for inability to move the lower limbs. The onset of his illness dated back to about nine months before admission when he noticed weakness, together with a heavy feeling of the lower limbs progressing to loss of sensation. Both these symptoms progressed so he sought medical advice. He also had difficulty in emptying his bladder completely. Physical examination disclosed that the pertinent findings were restricted to the nervous system. There were no voluntary movements in both lower limbs which were spastic and held in extension. Involuntary movements were not present and there was no muscular wasting. Examination of sensation disclosed a complete loss of appreciation of all modalities of sensation below the level of the xiphisternum. About the xiphisternum and up to about the level of the fourth dorsal dermatome there was a suggestion of dissociated sensory involvement with sparing of touch and loss of temperature and pain sensations. The knee and ankle jerks were exaggerated. An extensor type of plantar response was elicited on both sides. The patient had overflow incontinence of urine. The rest of the neurological and systemic examination was normal. Routine laboratory investigations disclosed no abnormal findings. A cisternal myelogram showed a complete arrest of " lipiodol" at the level of the second dorsal vertebra. A laminectomy was done and the only abnormality was a fusiform enlargement of the spinal cord. An incision along the posterior midline disclosed a fairly well encapsulated tumour that was removed from the substance of the cord without much difficulty. The tumour was about 1 cm. long and i cm. in diameter and tended to be more in the left than in the right half of the cord. Convalescence from surgery was uneventful and in about three months the patient had recovered sufficiently to be able to work eight to 10 hours a day on his farm. However, the loss of pain and temperature sensations between the fourth and the sixth dorsal dermatomes persisted. Four years later, in March, 1955, the patient experienced pain in the front of the chest on coughing and a heavy feeling in the lower limbs. The latter progressed to difficulty in walking and he was admitted on June 30, 1955, with weakness of the lower limbs, more marked on the left. Neurological examination revealed that the cranial nerves and upper limbs were normal. Both the lower limbs were spastic, the left more than the right. Power was markedly diminished on the left and moderately so on the right side. The muscles were not wasted and involuntary movements were absent. Examination of the deep tendon reflexes revealed that the knee and ankle jerks were markedly exaggerated on the left and brisk on the right side, with ankle clonus on the left. The abdominal skin reflexes were absent on both sides and an extensor type of plantar response was obtained bilaterally. Examination of the sensory system disclosed bilateral absence of pain, temperature, and touch sensations between the levels of the fourth and sixth dorsal dermatomes with retention of pressure and vibration sensations. Between the sixth and twelfth dorsal dermatomes all sensations were lost on the right and retained on the left side. Below this level all sensation was completely lost bilaterally. As on the previous admission the patient had an overflow incontinence of urine. On lumbar puncture, the cerebrospinal fluid contained 160 mg. protein per 100 ml. There were no cells. Cisternal myelography showed that the dye was arrested at the level of the second dorsal vertebra, which was at the same level as the previous block. The old laminectomy was therefore re-opened and the lamina of one vertebra above was nibbled to ensure adequate dissection of the extradural tissues and separation of the dura. The dura was tense and upon incision the cord was found to be enlarged and tense. The latter was incised as before and a well-encapsulated tumour, I cm. in length and about i cm. in diameter, extruded and was removed with ease. Convalesence from surgery was uneventful though slower than before and about six months after operation the patient has shown signs of improvement in that he is able to walk with the aid of a stick.