Regressive dystonia and cerebellar ataxia: two unusual symptoms in central pontine myelinolysis

Two patients with central pontine myelinolysis who presented with dystonia are described. In one, it was associated with cerebellar ataxia which spontaneously improved. In the second, dystonia progressively disappeared 6 months later. In both cases magnetic resonance imaging (MRI) revealed characteristic pontine lesions. Extrapontine myelinolysis involving the putamen was also observed in one patient. Even when the basal ganglia seem to be spared on MRI, dystonia is probably due to their involvement by myelinolysis. Cerebellar ataxia may be related to peduncular or cerebellar lesions or both.     

Magnetic resonance imaging in central pontine myelinolysis.

Magnetic resonance imaging (MRI) was performed in two patients in whom a clinical diagnosis of central pontine myelinolysis (CPM) had been made. MRI showed lesions in the pons in both cases about 2 years after the illness, at a time when the spastic quadriparesis and pseudobulbar palsy had recovered. The persisting abnormal signals in CPM are likely to be due to fibrillary gliosis. Persistence of lesions on MRI means that the diagnosis of CPM may be electively, after the acute illness has resolved.     

Central pontine and extrapontine myelinolysis: a report of 58 cases

In 58 cases with central pontine myelinolysis (CPM) and/or extrapontine myelinolysis, systematic examination of the central nervous system was performed. The demyelinating disease occurred in three subtypes: (1) CPM, in which the lesion was confined to the pons, (2) CPM combined with extrapontine myelinolysis and (3) exclusively extrapontine myelinolysis. Type (1) was found in 27 cases, (2) in 18 cases and (3) in 13 cases. Cerebellum and lateral geniculate body were the most frequently affected extrapontine regions. One case with an extreme extension of the lesions is described in detail. Extrapontine lesions seem to be more frequent and widespread than has been hitherto reported in the literature.     

Parkinsonism and dystonia in central pontine and extrapontine myelinolysis

Parkinsonism as well as dystonic signs are rarely seen incentral pontine myelinolysis and extrapontine myelinolysis. A 51yearold woman developed central pontine myelinolysis and extrapontine myelinolysis with parkinsonism after severe vomiting which followed alcohol and drug intake, even though marked hyponatraemia had beencorrected gradually over six days. Parkinsonism resolved four monthsafter onset, but she then exhibited persistent retrocollis, spasmodicdysphonia, and focal dystonia of her left hand. Although the medicalliterature documents three similar patients, this patient is differentas dystonic symptoms only developed four months after parkinsoniansigns had resolved.

     

Movement disorders as sequelae of central pontine myelinolysis: report of three cases.

In three survivors of central pontine myelinolysis, dystonia (in two patients) and rest tremor (in one) were sequelae. The onset of these movements occurred 3 weeks to 5 months after the initial presentation with central pontine myelinolysis. Magnetic resonance imaging revealed basal ganglia lesions suggestive of extra-pontine myelinolysis in all three patients. We propose that the movement disorders seen in our cases are clinical correlates of extra-pontine myelinolysis.     

A case of late adult-onset dentatorubral-pallidoluysian atrophy mimicking central pontine myelinolysis

We report the case of a 52-year-old man with late-onset dentatorubral-pallidoluysian atrophy (DRPLA). MRI findings of late-onset DRPLA usually showed the involvement of cerebral white matter lesions with high intensity on T2-weighted images (WI), in addition to brainstem, globus pallidus, and thalamus. But our patient did not present with abnormal manifestation of white matter lesions of the cerebrum. In addition, the appearance of pontine base was remarkably similar to central pontine myelinolysis (CPM). There is no reported case of DRPLA mimicking CPM in the literature, while there is one previous report of CPM with cerebellar ataxia without pyramidal tract involvement, and CPM may exhibit cerebellar ataxia. Although there is differentiation between CPM and DRPLA by the presence of the atrophy of brainstem and cerebellum, the characteristic MRI findings of pontine base may make it difficult to differentiate CPM with cerebellar ataxia from DRPLA with inconspicuous leukoencephalopathy. In such a situation, we should return to the clinical history and background of a patient, and, if necessary, DNA analysis should be performed for a definite diagnosis.     

Demyelination of the lateral geniculate nucleus in central pontine myelinolysis

Postmortem examination of the central nervous system in 6 of 9 patients with central pontine myelinolysis (CPM) revealed demyelination in the lateral geniculate nucleus (LGN). Histologically, the geniculate lesions consisted of myelin swelling and disintegration, largely in the central part of the nucleus, with preservation of axons and neuronal perikarya. The pathological changes resembled those found in the basis pontis in CPM.     

Computerized tomography in central pontine myelinolysis

We describe an autopsy-proven case of central pontine myelinolysis (CPM) with premortem computerized tomographic (CT) visualization of the lesion on two scans, performed with an interval of 2 weeks. This case demonstrates the capability of CT to support the clinical diagnosis of central pontine myelinolysis. Identification of the condition should facilitate prompt initiation of aggressive supportive care.     

Central pontine and extra-pontine myelinolysis in an alcoholic patient without hydro-electrolyte disturbances: case report

Central pontine myelinolysis (CPM) and extra-pontine myelinolysis (EPM) are different presentations of a demyelinating disorder of the brain more commonly associated with rapid correction of hyponatremia, spastic tetraparesia and pseudo-bulbar palsy. There are in the literature a few cases of CPM/EPM in patients without electrolyte disturbances. We report the case of a 39 year-old man with severe alcoholism, who presented with spastic tetraparesis and palsy of several cranial nerves, associated with lesions in the magnetic resonance compatible with CPM/EPM. The patient had a good follow-up after pulse therapy with corticosteroids.     

The corticobasal syndrome triggered by central pontine myelinolysis

Single case reports have described movement disorders including parkinsonism, dystonia and chorea, but not corticobasal syndrome as a consequence of central pontine and extrapontine myelinolysis. We report a case of a 61-year-old woman who developed progressive asymmetric parkinsonism with ideomotor apraxia and cortical sensory deficits following central pontine myelinolysis.     

Central pontine myelinolysis after liver transplantation

Eight adults and 3 children out of 85 patients who had neuropathologic examination after death following orthotopic liver transplantation showed central pontine myelinolysis (CPM). Four patients also had extrapontine myelinolysis. Eight patients had significant serum sodium changes. In 5, the fluctuation occurred perioperatively and 4 had a clinical picture consistent with CPM, although no patient had this as an antemortem diagnosis. We emphasize the role of hepatic dysfunction as a cause of CPM and recommend careful monitoring of electrolytes in the perioperative period of patients undergoing liver transplantation.     

Delayed onset movement disorders as a complication of central pontine myelinolysis

This report describes a case of central pontine myelinolysis occurring after a rapid correction of profound hyponatremia. Delayed-onset generalized dystonia and choreoathetosis then appeared. A small pontine myelinolysis was demonstrated by magnetic resonance images, but striatal myelinolysis could not be established. Aspects of movement disorders associated with the osmotic demyelination syndrome are briefly reviewed and discussed.     

Subclinical central pontine myelinolysis following liver transplantation

Central pontine myelinolysis (CPM) is a demyelinating disorder of unknown origin that almost exclusively affects the central portion of the basis pontis, and is one of the fatal neurological complications after liver transplantation. We describe two children with CPM detected incidentally after liver transplantation. To our knowledge, this is the first report of CPM diagnosed antemortem in children who had undergone liver transplantation. In our patients, there were no clinical manifestations associated with CPM. We conclude that, including silent cases such as our patients, CPM may be more prevalent than previously appreciated following liver transplantation.     

Belly dancer's syndrome following central pontine and extrapontine myelinolysis.

We report on a woman with delayed-onset of belly dancer's syndrome 5 months after central pontine and extrapontine myelinolysis (CPM/EPM) and severe hyponatriemia. This case demonstrates that basal ganglia lesions in EPM can be the underlying pathoanatomic substrate for the rarely observed belly dancer's syndrome. The sequential appearance of extrapyramidal symptoms might reflect an ongoing but ineffective or deficient remyelination process. The presence of CPM/EPM should be considered in patients with involuntary dyskinesias of the abdominal wall.     

Central pontine myelinolysis, an update

Central pontine myelinolysis (CPM) can be regarded as one of the demyelinating syndromes. First described by Adams et al. in 1959 in their chronic alcoholic patients, it has now been described in the malnourished, the chronically debilitated, the renal, the hepatic and the transplant patient among others. Pathologically, it is defined as a symmetric area of myelin disruption in the center of the basis pontis, although similar symmetric lesions have also been described occurring with CPM as well as independently in other brain areas (extrapontine myelinolysis or EPM) including the cerebellar and neocortical white/gray junctional areas, thalamus and striatum. Possible mechanisms include a hyperosmotically induced demyelination process resulting from rapid intracellular/ extracellular to intravascular water shifts producing relative glial dehydration and myelin degradation and/or oligodendroglial apoptosis. The process most often occurs during rapid rebalancing of the electrolyte parameters in the hyponatremic patient. Avoidance of CPM/EPM is dependent upon recognizing those patients with conditions pre-disposing them to osmotic myelinolysis and then moderating the rate of normalization of the electrolyte imbalance. The morbidity and mortality of CPM/EPM has been greatly reduced by recognition of pre-disposing conditions, increased understanding of the pathophysiology, intensive treatment, and rapid diagnosis and monitoring with advanced neuroimaging.     

A case of asymptomatic pontine myelinolysis

Central pontine myelinolysis is an acquired, non-inflammatory demyelinating lesion usually localized in the brainstem pons basis; it usually affects patients with a history of chronic alcoholism, malnutrition or dysionemia. The exact pathogenesis of myelinolysis is still unclear. A 69-year-old Caucasian male presented intensive headache and underwent cranial MRI that showed the typical feature of central pontine myelinolysis. Neurological valuation was negative. Other examinations included extensive blood tests, electroencephalogram and multimodal evoked potentials which all gave normal results. Alcohol abuse and malabsorption syndrome were excluded. The medical history revealed a continuative use of anti-depressive drugs and exposure to glue for years. Our patient may represent one of the rare cases of asymptomatic CPM. The actual reason why he presented this lesion is not clear, but we discuss the possible role in the etiopathogenesis of his chronic use of anti-depressive drugs and the exposure to glue and chemical agents.     

Central pontine myelinolysis.

Central pontine myelinolysis (CPM) is a demyelinating disease of the pons often associated with demyelination of other areas of the central nervous system (CNS). The term 'osmotic demyelinization syndrome' is used for pontine and extrapontine myelinolysis. In this paper, we are concerned with CPM although the extrapontine one is based on the same pathogenesis. Both share the diagnostic methods, and their prevention and therapy are the same. The etiology and pathogenesis of this disorder are unclear and will be discussed. However, almost all cases of CPM are related to severe diseases. Chronic alcoholism is still the most common underlying condition of CPM patients. In the literature, 174 cases of CPM have been reported in alcoholics since 1986, which is equivalent to an incidence of 39.4%. Likewise, 95 cases of CPM following the correction of hyponatremia have been documented since 1986 (21.5%). The role of hyponatremia and its correction will be outlined in the discussion of the pathogenesis of CPM. The third largest group of CPM cases are liver transplant patients (17.4%), with the development of CPM being attributed to the immunosuppressive agent cyclosporine in particular. Depending on the involvement of other CNS structures, the clinical picture can vary considerably. The large-scale introduction of magnetic resonance imaging has increasingly facilitated the antemortem diagnosis of CPM, although the radiological findings lag behind and do not necessarily correlate with the clinical picture. As yet, there is no specific therapy of choice. A number of therapeutic approaches have been tested and although they have not been compared with regard to their rate of success, they have all led to a substantial improvement in the prognosis of CPM.     

Evolving spectrum of movement disorders in extrapontine and central pontine myelinolysis

Extrapontine (EPM) and central pontine myelinolysis (CPM) are rare and frequently related to rapid correction of hyponatremia. We describe a 60-year-old woman who developed an unusual evolving spectrum of movement disorders secondary to EPM and CPM following intravenous sodium replacement therapy for severe hyponatremia. She presented initially with confusion, generalized coarse postural limb tremor, myoclonic jerks and quadriparesis. Subsequently her mental state improved and her tremor and weakness resolved. Over the following months, she developed progressive painful dystonia of her facial musculature and lower limbs. This gradually became generalized and associated with choreoathethosis in her limbs. In addition, she had increasing bradykinesia and rigidity, which responded poorly to levodopa treatment. Our case illustrates that while the myelin destruction occurs during the initial insult of the osmotic demyelinating process, its delayed clinical effects resulting from ineffective reorganization of neuronal structures may be progressive, evolve with time, and difficult to treat.     

Mild central pontine myelinolysis: a frequently undetected syndrome

Summary Over a period of 1 year we diagnosed central pontine myelinolysis (CPM) in five patients all of whom survived, two of them with complete functional recovery despite extensive lesions on cranial computerized tomography and magnetic resonance imaging.Diagnosis was based upon the combination of an acute brainstem dysfunction with typical neuroradiological features; a history of chronic alcoholism or a preceding hyponatremia may serve as a diagnostic hint.The spectrum of symptoms ranged from severe tetraplegia and cranial nerve palsies to latent signs of pyramidal tract lesions and discrete ocular motor abnormalities. In two patients pontine and extrapontine manifestations of demyelination were confirmed neuroradiologically; in one patient a solely extrapontine manifestation was present.Thus it is reasonable that: (1) the incidence of comparatively mild forms of CPM as well as extrapontine manifestations are more frequent than hitherto assumed, (2) the clinical outcome of the syndrome is better than expected from earlier fatal case reports and is quite independent of the extent of the lesion as it appears with brain imaging methods.     

Benign type of central pontine myelinolysis in alcoholism

Nine alcoholic patients with central pontine myelinolysis (CPM),who showed a favorable prognosis, are reported. The majority of them had taken part in binge drinking and had a subsequent consciousness disturbance for 18.1±10.9 (mean±SD) days. None of the patients had had acute correction of hyponatremia. Truncal ataxia and gait instability were present in most of the patients after recovery from the disturbance of consciousness. Most of them eventually gained independence, and magnetic resonance imaging showed that their pontine lesions tended to shrink. Electrophysiological studies detected prolonged latency between the I and III waves in auditory brainstem responses and between N11 and P13/14 onsets in the somatosensory evoked potentials. These clinical, radiological and electrophysiological findings should be of use in diagnosing CPM.