977 duration and few clinical signs, ACh sensitivities were reduced less than those in patients with chronic severe myasthenia, and the ACh-receptor-rich crests of the postsynaptic membrane were covered with particles suggestive of antibodies.’ Destruction of post-junctional membranes were observed especially in patients with severe myasthenia2 or myasthenic crisis,7 and it has been reported that those postsynaptic regions showing the greatest degenerative changes also show the greatest decrease

acetylcholine receptor8 (demonstrated by peroxidase-conjugated x-bungarotoxin). With the additional information that both IgG and C3 attach to segments of the postsynaptic membrane and degenerating folds9 in myasthenia gravis, it is likely that the destructive changes of the end-plate result from an autoimmune reaction. Now that the pathophysiology of myasthenia gravis and myasthenic weakness is more clearly understood, studies concerned with how these changes occur (patho-

tory error in the assay. The similarity between this case and the one described by Melsom et al.’ makes one wonder whether any other clinicians have observed such a discrepancy. Hutt Hospital, New Zealand

Departments of Neurology and Pharmacology and Experimental Therapeutics,

School of Medicne, University of Maryland, Baltimore, Maryland 21201, U.S.A.

RICHARD F. MAYER EDSON X. ALBUQUERQUE

PERNICIOUS ANÆMIA WITH NEUROMYELOPATHY AND NORMAL SERUM-VITAMIN-B12

SIR,-Melsom et al.’ described a patient with a neuropathy which responded to treatment with vitamin BJ2’ in whom the pretreatment serum-vitamin-B,, was normal. I describe here a similar case. A 35-year-old fair-haired man presented with a 3 month history of paraesthesiae of the lower limbs and progressive difficulty in walking. He had had erectile impotence for 6 months and his wife had noticed a gradual impairment in his memory over almost a year. There was no relevant family history, his diet was normal, and he was a teetotaller. On examination, he was clinically anaemic and unable to walk unaided. He had bilateral extensor plantars, absent vibration sense, and very reduced proprioception in the lower limbs. There was diminished cutaneous sensation distally in a stocking distribution. His mental activity was slow and recent memory poor. Hxmatological findings were: haemoglobin 7-6 g/dl; packed cell volume 0.21 ; mean corpuscular haemoglobin concentration 30 g/l; leucocyte count 3.4x109/l; platelets normal. Macrocytosis and hypersegmented neutrophils were found. The bonemarrow had a typical untreated megaloblastic picture. There was histamine-fast achlorhydria and a ’Dicopac’ (modified Schilling) test gave a 57CO/58CO ratio of 2-14, indicating intrinsic-factor deficiency. Parietal-cell antibodies were present. Red-blood-cell folate was 700 nmol/1 (normal 360-2040) and serum-vitamin-B,2 was 227 pmol/1 (normal 96-485). VitaminB,2-binding capacity was normal. Vitamin-BJ2 neuromyelopathy was diagnosed and hydroxocobalamin was given (250 µg daily). 3 days later, his reticulocyte-count was 13-8%, and after 10 days he could walk unaided. After 5 weeks paraesthesiae, proprioception, and general mental state had improved although vibration sense was still impaired and spastic signs persisted in the lower limbs. Hxmoglobin was 12-4g/dl and his impotence had improved. This patient responded to treatment with vitamin BJ2’ Treatment had begun by the time his pretreatment serum-B,2 was assayed and the result could not be checked. The most likely explanation for normal vitamin B12 in a patient with the neurological complications of pernicious anxmia is a labora-

M. MAHOOD

HERPES-SIMPLEX INFECTION PRESENTING AS BRAINSTEM ENCEPHALITIS

in

genesis) are of utmost importance.

JOHN

SIR,-We have seen a case of herpes-simplex infection presenting1 as brainstem encephalitis similar to one recently described. 4 days before admission, the patient, aged 4 years 8 months, complained of pain in his teeth. Over the next 24 h he became somnolent with twitching of the right side of his face, and had difficulty in swallowing and talking. 2 days later he was admitted to a local hospital in a febrile, lethargic, and dehydrated condition. Although he was hypotonic, tendon reflexes were normal. There was myoclonic twitching of the face and leftsided lower motor neurone 7th nerve weakness. Lumbar puncture yielded normal spinal fluid under normal pressure. Increasing lethargy and confusion and his inability to swallow prompted his transfer to our hospital on the fourth day of his illness. Trismus, bilateral facial weakness, increased muscle tone in all extremities with brisk deep tendon reflexes and 1.

Ellison, P. H., Hanson, P. A. Pediatrics, 1977, 59, 240.

Fig. 1-Computerised tomography ing of the pons. The

rest

scan

suggesting

some

swell-

of the brain ventricular system is normal.

7 Mayer.

R. F., Albuquerque, E. X., Rash, J. E, Hudson, C. S. Trans. Am. Neurol. Ass (in the press). 8 Engel, A. G., Lindstrom, J. M., Lambert, E. H., Lennon, V. A. Neurology,

9

1977, 27, 307. A. G., Lambert,

Engel,

E. H.,

Howard, F. M. Mayo Clin Proc. 1977, 52,

267. 1

Melsom, H., Kornstad, S., Abildgaard, U. Lancet, 1977, i, 803.

Fig. 2--Computerised tomography

scan showing enlargement of ventricles with marked dilatation of sylvian fissures and low attenuation around both parietal regions. Considerable diffuse atrophy and additional focal brain destruction

are

suggested.