Idiopathic torsion dystonia associated with lesions of the basal ganglia

The Dystonias

Dystonia is a difficult problem for both the clinician and the scientist. It is sufficiently common to be seen by almost all physicians, yet uncommon enough to prevent any physician from gaining broad experience in its diagnosis and treatment. Each case represents a difficult challenge even to the specialist. The basic scientist is faced with investigating a disorder that is without relevant animal models and which is so rare that obtaining suitable tissue for study is a major obstacle. Dystonia may be idiopathic, or associated with lesions from many sources, including a variety of rare diseases. If idiopathic, it may be genetically transmitted or sporadic. If genetically transmitted, it may be generalized or focal, with symptoms varying in different members of the same family. It may be refractory to treatment, or it may respond to any one of a number of individual drugs that have very different mechanisms of action. For idiopathic dystonias, no clear method of genetic transmission has been established and no consistent pathology identified.

Familial dystonia and choreoathetosis in three generations associated with bilateral striatal necrosis

Nine cases of dystonia and choreoathetosis (six females and three males) have developed in three generations of a single family. There has been one death. Neuropathologic examination disclosed bilateral striatal necrosis. In this family, the neurologic disorder has evolved gradually or in association with a febrile illness. There has been no neurologic recovery. The disease is worse in females, has been transmitted only through females, and shows incomplete penetrance and anticipation. The maternal inheritance pattern suggests either an autosomal dominant trait also affecting male reproductive ability or a defect involving the mitochondrial genome.

Bilateral striatal necrosis, dystonia and optic atrophy in two siblings

Two siblings developed a neurological disorder in the first decade characterised by generalised dystonia, hypokinesia, and subacute visual loss. CT and serial MRI examinations showed bilateral lesions of the striatum, mainly in the putamen. The classification of these patients is discussed in relation to infantile bilateral striatal necrosis (IBSN), Leigh's disease, and Leber's optic neuropathy. The literature shows a clinical and aetiopathogenetic overlap between these syndromes. In our cases parental consanguinity and the involvement of a single generation suggest a new clinical condition with autosomal recessive transmission.

Hereditary spastic dystonia: a new mitochondrial encephalopathy? Putaminal necrosis as a diagnostic sign

A large kindred, in which either Leber's hereditary optic atrophy, or a hereditary spastic dystonia, or a combination of both manifested over many generations was restudied after the first report on it in 1964. NMR scans revealed bilateral, and, in two patients with hemidystonia, unilateral necrosis with shrinkage of the putamen, in one case associated with total disappearance of the head of the caudate nucleus. Except for age-appropriate cortical atrophy in one instance, no other changes were observed in the brain, brainstem, and cerebellum. The putaminal necrosis appears as typical "striatal slits" on the NMR scans. It is argued that this rare disease, since the princeps description in 1964 only reported in England (1986) and the U.S.A (1986), is most likely a singular type of mitochondrial encephalopathy: it is associated with Leber's optic atrophy, and the NMR changes observed have been signalled in other mitochondrial encephalomyelopathies, such as Leigh's disease and MELAS.

Partial cytochrome b deficiency and generalized dystonia

An 18-year-old female had clinical features of idiopathic torsion dystonia with bilateral hypodense putaminal lesions on computed tomography. Mitochondrial encephalomyopathy was suspected because of persistent lactic acidemia and myopathy. Studies of oxidative metabolism on isolated skeletal muscle mitochondria revealed partial cytochrome b deficiency indicating a defect in the cytochrome b- c1 complex. This finding represents a unique, multisystem syndrome of progressive dystonia, putaminal degeneration, myopathy, and mitochondrial cytochrome b deficiency. Mitochondrial metabolic disorders may be a cause of torsion dystonia when other known associated factors are absent.