We report here the case of a patient
We report here the case of a patient with probable genetic prion disease with a Creutzfeldt-Jakob disease-like phenotype associated with a rare PRNP E196K mutation who initially exhibited atypical clinical manifestations principally characterized by behavioral abnormalities.
Case report An 80-year-old right-handed man was admitted to our stroke unit because he had exhibited a sudden loss of balance 6h earlier. The patient had a history of treated hypertension, type-2 diabetes, myocardial infarction, and peripheral vascular disease, and asymptomatic left internal carotid artery stenosis. In contrast, he had no particular familial medical history. At admission, we noted a left cerebellar syndrome associated with dysarthria and dysphagia. Both muscular strength and sensation were normal, as were deep tendon reflexes. The left plantar reflex was extensor. Cerebral Magnetic Resonance Imaging (MRI) revealed multiple deep hyperintense lesions on T2-weighted sequences, compatible with lacunes, which were also found within the brainstem (Fig. 1). On diffusion-weighted MRI, two hyperintense lesions were noted in the right caudate nucleus and the left cerebellar hemisphere with a decreased attenuated apparent Safingol synthesis coefficient (ADC), which was suggestive of a recent infarction of these territories (Fig. 1). MR angiography showed stenosis of both the left internal carotid artery, and the initial portion of the left vertebral artery, while the right carotid artery was normal. These results were confirmed by conventional angiography. Trans-esophageal echo-cardiography and routine laboratory exams were normal. Therefore, the initial diagnosis was cerebellar and cerebral infarcts. Conventional treatment of stroke was performed. Unfortunately, during the 2 weeks following his admission, the patient exhibited progressively worsening abnormal behavior characterized by hallucinations and intense agitation interspersed with periods of severe apathy. In addition, several episodes of clonic jerk affecting the right upper limb were observed. His relatives mentioned that he had recently (3 months) experienced difficulties in using his computer keyboard, and sleep disorders characterized by repeated periods of severe insomnia. The neurological examination revealed ideomotor apraxia, which was not searched for during the first examination. Cerebral MRI was repeated, but revealed no additional lesions. Repeated electroencephalography (EEG) showed a general slowing of the basic activity, as well as several episodes of triphasic waves, with neither periodic activity nor recorded seizure. The cerebral spinal fluid (CSF) was normal for cell count and blood-CSF-barrier function but 14.3.3 protein was detected. Direct sequencing of the PRNP gene open reading frame revealed an E196K mutation associated with homozygosity for methionine at codon 129. The patient was diagnosed with probable genetic prion disease with a Creutzfeldt-Jakob phenotype. The patient rapidly developed severe akinetic mutism and coma, and died 3 months after his admission. No autopsy was performed.
Discussion The clinical presentation of our patient, which justified his admission to hospital, i.e. cerebellar syndrome associated with dysarthria and dysphagia, was highly suggestive of an acute stroke. The hyperintense lesion in the left cerebellar hemisphere on the diffusion-weighted MRI associated with the stenosis of the initial portion of the left vertebral artery on the MR angiography was compatible with a left cerebellar hemisphere infarct. However, another lesion was found in the right caudate nucleus without stenosis of the arteries supplying this territory. This lesion was initially considered an infarct, but the clinical progression of our patient and the subsequent findings went against this assumption. Actually, several cases of CJD with stroke-like onset have been described in the literature , , and in a systematic review , this atypical clinical presentation accounted for 5.6% of 532 database patients with definite or probable CJD. In their CJD patient with an onset mimicking a stroke, Szabo et al. reported a hyperintense lesion on the diffusion-weighted MRI and a reduced ADC in the head of the caudate, similar to that observed in our patient, as well as a second hyperintense lesion in the ventral part of the putamen on the right . Follow-up MRI revealed persisting ADC reduction, indicating rather a continuous progressive degenerative destruction of neuronal tissue than what the natural history of ADC and tissue changes in stroke would suggest . In our observation, the ADC was not measured in the second MRI, and it is not possible to draw any definite conclusions on the exact nature of the lesion in the right caudate nucleus. Moreover, a hyperintense signal in the putamen and caudate head has been described as the most consistent finding in CJD . Hence, we can assume that our patient presented both stroke and a probable genetic prion disease with a Creutzfeldt-Jakob phenotype, but the potential relationship between these two events remains unclear.