Creutzfelt-Jakob disease presenting hyperparathyroidism

Creutzfeldt-Jakob-Like Syndrome due to Hypercalcemic Encephalopathy

Hypercalcemia can cause a subacute syndrome of progressive dementia and marked changes in the electroencephalogram (EEG). We report a case of iatrogenic hypercalcemia with a close correlation between the clinical course and the EEG changes. A 73-year-old woman presented with a subacute syndrome of progressive dementia and bursts of 1.5 to 2 Hz intermittent rhythmic delta activity superimposed on a low-voltage background activity in the EEG. Clinical and EEG abnormalities rapidly resolved after normalization of serum calcium levels. As part of the diagnostic workup of a subacute progressive dementia, a serum calcium level and an EEG should be obtained to detect a Creutzfeldt-Jakob like syndrome in hypercalcemia. Unlike in Creutzfeldt-Jakob disease, and Creutzfeldt-Jakob-like syndrome induced by lithium intoxication, there are rarely myoclonic jerks and periodic discharges in hypercalcemic encephalopathy.

Neurologic disorders of mineral metabolism and parathyroid disease

Disorders of mineral metabolism may cause neurologic manifestations of the central and peripheral nervous systems. This is because plasma calcium stabilizes excitable membranes in the nerve and muscle tissue, magnesium is predominantly intracellular and is required for activation of many intracellular enzymes, and extracellular magnesium affects synaptic transmission. This chapter reviews abnormalities in electrolytes and minerals which can be associated with several neuromuscular symptoms including neuromuscular irritability, mental status changes, cardiac and smooth muscle changes, etc.

Reversible dementias

The causes of potentially reversible dementia syndromes are legion, as many perturbations of body chemistry can lead to dysfunction of higher cortical function, including the chemical interventions we call medication. It is vital for the cautious clinician to take a painstaking history to develop a differential diagnosis of potential causally related reversible phenomena. This, coupled with an extensive examination and a widecast net of serological, and when appropriate, cerebrospinal, electrophysiologic, and neuroimaging studies can increase the potential for discovering these mimics of the primary neurodegenerative dementias. While some cases of reversible dementia will be obvious from history and physical and only require a few confirmatory tests or even just a trial of treatment (or often, discontinuation of a suspect treatment), it is worthwhile to perform more extensive work-up in cases of dementia, as the costs to allowing our patients to remain in an incapacitated, possibly progressive, state of disability far outweigh the costs of ruling out reversible causes. This chapter provides a lengthy, though by no means exhaustive, review of etiologies and work-up for the currently recognized reversible dementias.

Creutzfeldt-Jakob disease presenting as hyperparathyroidism and generalized tonic status epilepticus

Creutzfeldt-Jakob disease is the most common disorder among the very rare human transmissible subacute spongiform encephalopathies. Sporadic, familial or iatrogenic forms of the disease can be seen. The common presentations of the disease include rapidly progressive cognitive decline, behavioral changes, visual disturbances and cerebellar dysfunction. Hyperparathyroidism and toxicity of lithium and bismuth have been reported to induce similar symptoms and EEG findings, leading to a Creutzfeldt-Jakob like syndrome. We report a very rare case of Creutzfeldt-Jakob disease presenting with hyperparathyroidism and generalized tonic status epilepticus.

[Lithium-induced encephalopathy mimicking Creutzfeldt-Jakob disease]

INTRODUCTION

Creutzfeldt-Jakob disease (CJD) has a poor prognosis. Certain clinical presentations can be suggestive yet mimic a curable disease.

OBSERVATION

In the present study, we report the case of a 67-year-old man with a one-month history of progressive dementia, with myoclonic jerks and cerebellar syndrome suggesting a diagnosis of Creutzfeldt-Jakob encephalopathy. He had been treated for 9 years with lithium for a bipolar disorder. The results of the different investigations and the favorable course after discontinuation of lithium were in favor of the diagnosis of drug-induced Creutzfeldt-Jakob syndrome.

CONCLUSION

This case illustrates the importance for researching a curable etiology in presence of clinical features suggesting a CJD.