A case of cerebral Whipple's disease initially presenting with isolated focal myoclonus

Isolated central nervous system Whipple disease

Background:

Whipple disease (WD) is an infection caused by Tropheryma whipplei, which might present in three different forms: classical, localized, and isolated in the central nervous system (CNS).

Methods:

We report the result of a systematic review of the literature on WD unusually presenting with exclusively neurological symptoms, including two previously unpublished cases. A description of two cases with isolated CNS WD was performed, as well as a literature search in Cochrane, Scielo, and PubMed.

Results:

Two male adult patients presented with exclusively neurological symptomatology. Both magnetic resonance imaging (MRI) showed an intracranial mass suggestive of brain tumor. The histopathological examination was consistent with WD, with no systemic involvement. In the review of the literature, 35 cases of isolated CNS WD were retrieved. The median age at diagnosis was 43.5 (IQR 31.5–51.5). In 13 patients, the MRI showed a brain mass consistent with a brain tumor. The most common finding in the biopsy was the periodic-acid Schiff-stained foamy macrophages. Only five cases presented the pathognomonic sign of oculomasticatory myorhythmia. Thirteen cases had an adverse outcome that resulted in death during follow-up, whereas another 13 improved. The other nine patients remained stable or presented moderate improvement.

Conclusion:

Isolated CNS WD is a rare disease that should be considered among the differential diagnosis of CNS mass lesions. Brain biopsy is necessary to establish the diagnosis. It is stressed in the literature that an extended antibiotic course is required to prevent relapses and to control the disease.

Progressive dementia associated with ataxia or obesity in patients with Tropheryma whipplei encephalitis

Background

Tropheryma whipplei, the agent of Whipple's disease, causes localised infections in the absence of histological digestive involvement. Our objective is to describe T. whipplei encephalitis.

Methods

We first diagnosed a patient presenting dementia and obesity whose brain biopsy and cerebrospinal fluid specimens contained T. whipplei DNA and who responded dramatically to antibiotic treatment. We subsequently tested cerebrospinal fluid specimens and brain biopsies sent to our laboratory using T. whipplei PCR assays. PAS-staining and T. whipplei immunohistochemistry were also performed on brain biopsies. Analysis was conducted for 824 cerebrospinal fluid specimens and 16 brain biopsies.

Results

We diagnosed seven patients with T. whipplei encephalitis who demonstrated no digestive involvement. Detailed clinical histories were available for 5 of them. Regular PCR that targeted a monocopy sequence, PAS-staining and immunohistochemistry were negative; however, several highly sensitive and specific PCR assays targeting a repeated sequence were positive. Cognitive impairments and ataxia were the most common neurologic manifestations. Weight gain was paradoxically observed for 2 patients. The patients' responses to the antibiotic treatment were dramatic and included weight loss in the obese patients.

Conclusions

We describe a new clinical condition in patients with dementia and obesity or ataxia linked to T. whipplei that may be cured with antibiotics.

Myoclonus

Myoclonus can be classified as physiologic, essential, epileptic, and symptomatic. Animal models of myoclonus include DDT and posthypoxic myoclonus in the rat. 5-Hydrotryptophan, clonazepam, and valproic acid suppress myoclonus induced by posthypoxia. The diagnostic evaluation of myoclonus is complex and involves an extensive work-up including basic electrolytes, glucose, renal and hepatic function tests, paraneoplastic antibodies, drug and toxicology screens, thyroid antibody and function studies, neurophysiology testing, imaging, and tests for malabsorption disorders, assays for enzyme deficiencies, tissue biopsy, copper studies, alpha-fetoprotein, cytogenetic analysis, radiosensitivity DNA synthesis, genetic testing for inherited disorders, and mitochondrial function studies. Treatment of myoclonus is targeted to the underlying disorder. If myoclonus physiology cannot be demonstrated, treatment should be aimed at the common pattern of symptoms. If the diagnosis is not known, treatment could be directed empirically at cortical myoclonus as the most common physiology. In cortical myoclonus, the most effective drugs are sodium valproic acid, clonazepam, levetiracetam, and piracetam. For cortical-subcortical myoclonus, valproic acid is the drug of choice. Here, lamotrigine can be used either alone or in combination with valproic acid. Ethosuximide, levetiracetam, or zonisamide can also be used as adjunct therapy with valproic acid. A ketogenic diet can be considered if everything else fails. Subcortical-nonsegmental myoclonus may respond to clonazepam and deep-brain stimulation. Rituximab, adrenocorticotropic hormone, high-dose dexamethasone pulse, or plasmapheresis have been reported to improve opsoclonus myoclonus syndrome. Reticular reflex myoclonus can be treated with clonazepam, diazepam and 5-hydrotryptophan. For palatal myoclonus, a variety of drugs have been used.