Toxoplasma encephalitis in a HIV patient: unusual involvement of the corpus callosum.

In patients with acquired immuno-deficiency syndrome, the differential diagnosis between primary brain lymphoma and toxoplasma encephalitis is not radiologically always straightforward, especially in the presence of a solitary cerebral lesion. In this context, involvement of the corpus callosum is almost exclusively associated with primary brain lymphoma. We describe here an HIV-infected patient who presented with a single and large cerebral lesion affecting the corpus callosum, suggestive of primary brain lymphoma on MRI-scan but who nonetheless responded clinically and radiologically to an anti-toxoplasma drug trial confirming the diagnosis of toxoplasma encephalitis.

Unusual occurrence of cervical myelopathy in a case of Stickler's syndrome.

We report the occurrence of progressive Brown-Séquard syndrome as the presenting clinical feature of cervical spondylosis in a young patient with Stickler's syndrome.

Mitochondrial myopathy of childhood associated with depletion of mitochondrial DNA.

We have studied five children with mitochondrial myopathy manifesting within or soon after the first year of life. Muscle biopsies showed ragged-red fibers and decreased respiratory chain activity. All five patients had a severe decrease (2 to 34% of normal) in the amount of muscle mitochondrial DNA (mtDNA). The depletion of mtDNA correlated with absence of mtDNA-encoded translation products and with loss of cytochrome c oxidase enzyme activity in individual muscle fibers. This mitochondrial myopathy of childhood illustrates one phenotypic expression of a novel pathogenetic mechanism in mitochondrial diseases, the specific depletion of mtDNA in affected tissues.

Movement disorders due to cerebral Toxoplasma gondii infection in patients with the acquired immunodeficiency syndrome (AIDS).

Hemichorea and parkinsonism are unusual manifestations of cerebral toxoplasmosis in patients with AIDS. We here describe two such cases and we reviewed extensively the literature (through computer searches using MEDLINE) for other reported instances. In our patients, unlike the other neurological symptoms, the response of the movement disorders to anti-toxoplasmosis therapy was delayed and only partial. We demonstrate that tetrabenazine is a valuable additional symptomatic treatment for choreic movements in one of our patients. We emphasize that, among patients suffering from AIDS, particularly in countries with high prevalence of toxoplasmosis, the occurrence of movement disorders should first suggest the diagnosis of cerebral toxoplasmosis.

[Reversible spastic triparesis with hyperammonemia]. / Triparésie spastique "ammoniacale" réversible.

A 24-years old alcoholic man was admitted for a spastic triparesis. Despite mild hepatic failure without objective portosystemic shunt, this encephalomyelopathy was related to an hyperammonemia. This case is unusual by the recovery of the neurological deficit.

[Vasculitis of the central nervous system]. / Les vasculites du système nerveux central.

The involvement of the central nervous system (CNS) by a vasculitic process is an infrequent but serious manifestation of several systemic diseases. The neurological disturbances are most often due to cerebral ischemia; however, vascular inflammation is not the only pathogenetic factor of CNS disease in systemic vasculitis. Most often, the specific diagnosis of CNS vasculitis depends on identifying clinical or histologic evidence of target organ involvement outside the CNS. The primary angiitis of the central nervous system (PACNS) is a rare form of vasculitis limited to the central nervous system. The diagnosis of this disorder is difficult owing to its various clinical manifestations and to the poor specificity of the neurological investigations. The demonstration by cerebral angiography and/or tissue examination of an arteritic process is mandatory for establishing this diagnosis.

Auriculo-ventricular block and distal myopathy with rimmed vacuoles and desmin storage.

A young patient had an auriculo-ventricular block and a distal myopathy with muscle biopsy findings suggestive of inclusion body myositis. What was most unusual was the presence of numerous sarcoplasmic bodies identified as desmin by electron microscopy and immunocytochemistry. The nosological situation of this condition is discussed.

[Sporadic Z disk myopathy with accumulation of rods and cytoplasmic bodies]. / Myopathie sporadique du disque Z avec accumulation de bâtonnets et corps cytoplasmiques.

An unusual myopathy with extensive myofibrillar degeneration related to the Z disk is reported. Focal Z disk disappearance, accumulation of numerous rods and cytoplasmic bodies and some rimmed vacuoles represented the major pathologic features of this sporadic muscular disorder, sharing common clinical and electrophysiological features with inclusion body myositis. This diagnosis was excluded because all nuclei appeared normal and 15-18 nm filaments were not observed in cytoplasm or in the vicinity of membranous whorls. Intramuscular innervation was studied by vital staining with methylene blue: the terminal innervation ratio was normal, indicating a myopathic disorder. The relationship between the present disorder and cytoplasmic bodies and nemaline myopathies is discussed.

[Mitochondrial encephalopathy affecting only the central nervous system]. / Encéphalopathie mitochondriale avec atteinte exclusive du système nerveux central.

A 32 year-old diabetic woman presented with an acute coma followed by epileptic seizures, aphasia and constructive apraxia. No ischemic lesion was demonstrated by CT scan and carotid angiograms. The other investigations showed sensorineural hearing loss, retinal degeneration, calcifications of the basal ganglia and lactic acidosis. The follow-up was marked by pseudo-dementia with personality disorders, memory deficits, behavioural changes, migrainous and epileptic features. Although there was no sign of muscular deficiency, a muscular biopsy showed characteristic ragged-red fibers and mitochondrial abnormalities at electron microscopy. The muscular biopsy enables us to classify this case as a mitochondrial encephalopathy similar to the MELAS syndrome. The stroke-like episodes are probably caused by a specific angiopathy involving the mitochondria of brain vessels.

Type 2 fiber predominance in muscle cramp and exertional myalgia.

In patients complaining of muscle cramps and exertional myalgia, we found a significant decrease of type 1 muscle fiber proportion in comparison with a control group. The possible mechanism of this change is discussed.

Familial myopathies with restricted distribution, facial weakness and inflammatory changes in affected muscles.

A myopathy characterized by restricted involvement of few muscles and inflammatory cell infiltration was observed in three families. In the first family, clinical features, hereditary transmission and biopsy findings were consistent with the diagnosis of facioscapulohumeral dystrophy. However in three of the four affected members, the occurrence of atrophies was specifically initiated by severe muscular pain. In the second family two 8-year-old identical twins had both marked facial weakness and atrophy limited to the right quadriceps femoris. In the third family, marked asymmetry of muscular wasting in the upper limbs was found in the 17-year-old daughter of a man suffering from facial and axial weakness. The indication of corticotherapy in such cases is discussed.

Unclassified familial myopathy resembling Steinert disease, without myotonia.

A familial myopathy with predominantly proximal muscle atrophy is described. Although several clinical features such as sternomastoid and brachioradialis muscle involvement suggested Steinert disease, myotonia was not demonstrated by clinical examination or EMG. Histological data were consistent with myotonic dystrophy.

[Changes in the motor units in patients with traumatic paraplegia]. / Modifications des unités motrices chez des malades atteints de paraplégie traumatique.

Neuromuscular biopsies were obtained in 10 patients with traumatic spinal cord lesions at various levels and in one patient with cerebral lesions due to a long lasting coma. In all cases, there was a rapid onset of both fibers types atrophy, with numerous transitional type III and intermediate fibers. Only the two patients with cervical lesions had an increased terminal innervation ratio suggesting denervation. Our observations do not support the hypothesis of a transneuronal degeneration. These changes cannot be related to disuse only as the atrophy does not preferentially involve type II fibers. The underlying neural mechanism of spasticity in muscle of patients with cortico-spinal lesions could explain the change of the histochemical pattern of the muscle fibers.

Orthostatic hypotension with lower brain stem glioma.

A patient with long standing orthostatic hypotension with fixed pulse rate due to involvement of the medullary regulatory centres by a lower brain stem glioma is described.