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| Year : 1999 | Volume
: 47
| Issue : 1 | Page : 78-9 |
Myasthenia gravis with chronic inflammatory demyelinating polyneuropathy - A case report.
Shankar V, Sayeed ZA
Department of Neurology and Laboratory of clinical Neurophysiology, Apollo Institute of Neurological Sciences, Apollo Hospital, Chennai, Tamil Nadu, India.
Correspondence Address:
Department of Neurology and Laboratory of clinical Neurophysiology, Apollo Institute of Neurological Sciences, Apollo Hospital, Chennai, Tamil Nadu, India.
How to cite this article:
Shankar V, Sayeed Z A. Myasthenia gravis with chronic inflammatory demyelinating polyneuropathy - A case report. Neurol India 1999;47:78 |
A nineteen year old male student developed double vision with drooping of eyelids at the age of sixteen. The symptoms had diurnal variation. A diagnosis of myasthenia gravis was made, based on decremental response to repetitive nerve stimulation and correction of ptosis and diplopia with intravenous prostigmine. He was started on mestinon in a dose of 180 mg/day and underwent thymectomy through the median sternotomy approach. He remained asymptomatic with mestinon 180 mgm/day, for the next two and a half years. He then developed difficulty in gripping objects with the hands and in lifting the arms above the shoulders. There was difficulty in raising up from the squatting position and tripping of toes. He noted thinning of limbs. The symptoms were of gradual onset and progressed over a period of three months.
On examination the higher mental functions were normal. He had bilateral ptosis with external ophthalmoplegia. Bilateral facial and bulbar weakness was present. Small muscles of the hand and feet were wasted. The muscle power universally was grade 4 on the MRC scale. Bulbar and limb muscles showed fatiguability. All deep tendon reflexes were absent. Sensory and cerebellar systems were within normal limits. Administration of IV prostigmine (1mg diulted in 8 ml of distal water injected at the rate of 1 ml every 30 seconds) resulted in recovery of ocular movements with partial improvement in ptosis. Repetitive nerve stimula tion at 3Hz evoked a decremental response of 8% in the facial muscle, 20% in the deltoid and 27% in the abductor pollicis brevis muscle. Antiacetyl choline receptor antibodies were positive on `ELISA' test. The lateral popliteal and posterior tibial nerves were not stimulable. The upper limb motor conduction and sensory conduction values are given in [Table I]. CSF examination showed 50mg/dl of protein with no cells.
Right sural nerve biopsy showed a) increased endoneural collagen, b) schwann cell prominence, c) sprinkling of inflammatory cells around endo and perineural vessels. 4) K - Pal stain showed severe loss of large and small myelinated fibres with presence of remyelinating fibres, Those findings were considered compatible with the diagnosis of demyelinating neuropathy, viz. CIDP. Biopsy of quadriceps muscle showed preservation of fascicular architecture with some atrophic fibres showing clumping of sarcolemml nuclei. There was no increase in endomysial collagen. These findings were considered compatible with the diagnosis of neurogenic atrophy.
Patient was treated with mestinon and neostigmine. Prednisolone was started in a dose of 1 mg/kg body weight for early immunosuppression along with cyclophosphamide in a dose of 1 mg/kg body weight was started concurrently. Prednisolone was tapered and withdrawn after 3 months. He was being maintained on cyclophosphamide and mestinon. Follow up revealed decrease in ptosis. Extra ocular movements and bulbar functions had returned to normal. Power in all the 4 limbs improved to grade 5. Improvement continued to be maintained during the follow up period of 1 year on cyclophosphamide and mestinon.
Our patient had myasthenia gravis as evidenced by a positive prostigmine test, decremental response on repetitive nerve stimulation and positive anti acetyl choline receptor antibodies. He also had CIDP as evidenced by inexcitable lower limb nerves with upper limb nerves showing prolonged distal latencies, prolonged conduction ve locity, delayed F latency in a patchy manner, raised CSF protein and nerve biopsy consistent with CIDP. The simultaneous occurrence of myasthenia gravis and CIDP is rare. A single case has been documented by Inatus et al.[1] Both the diseases are considered to be antibody mediated, one against the peripheral nervous system and the other against the neuromuscular junction. There may exist an autoimmune mechanism common atleast in part to both CIDP and myasthenia gravis in our patient. However, the coincidental occurrence of two disorders cannot be excluded.
| 1. | Inatus A, Ohi-T, Shioya K, et al : A case of myasthenia gravis occcuring in the period of remission of chronic inflammatory demyelinating polyradiculoneuropathy. Rinsha-Simkeignku 1992; 32 : 878-879.  |
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