P 164 Parietal stroke mimicking the Heidenhain variant of Creutzfeldt-Jakob Disease

The Heidenhain variant of Creutzfeldt-Jakob disease (CJD) is a rapidly progressive neurodegenerative disease with an occipito-parietal focus.It initially presents with visual disturbances such as visual agnosia or cortical blindness ( Kropp et al., 1999 ).After presentation of early visual symptoms, rapid progression of dementia and death follows.While the Heidenhain variant matches neuropathological criteria of CJD, differential diagnosis from other neurological disorders using biomarkers from electroencephalography (EEG), magnetic resonance imaging (MRI), and cerebrospinal fluid (CSF) reveal low sensitivity and specificity.As a consequence, these tools may lead to an erroneous diagnosis of the Heidenhain variant. We report about a 81-year old female who was transferred to the intensive care unit due to a generalized tonic-clonic seizure followed by prolonged somnolence, additionally exhibiting myoclonic jerks of the distal legs, left horizontal gaze palsy and horizontal nystagmus to the right.A history of cognitive decline including short-term memory and word-finding difficulties as well as visuospatial and visuoconstructive deficits over the last few weeks was reported. Initial EEG revealed 1.5 Hz left lateralized periodic sharp-wave and polyspike-wave complexes of high amplitude and triphasic morphology suspicious for CJD. Brain MRI showed a hyperintense lesion in the left occipito-parietal lobe on diffusion-weighted and FLAIR sequences, respectively.Protein 14-3-3 was positive in CSF (ELISA). However, RT-QuIC confirmatory test was negative.Other serum and CSF parameters including anti-neuronal antibodies were negative.Given this information, is it reasonable to consider the Heidenhain variant of CJD? The patient suffered from a cardioembolic stroke due to atrial fibrillation affecting the parietal branches of the middle cerebral artery.Edoxaban had been removed three weeks previously because of repeated falls.During ICU treatment, the patient developed a prolonged nonconvulsive status epilepticus (NCSE) characterized by deep coma without significant motor phenomena.EEG was refractory to an initial antiepileptic drug treatment, but finally returned to normal with valproate monotherapy.The patient, however, remained comatose until transfer to rehabilitation, but she regained consciousness two weeks later. This case points out that a parietal stroke with complicating NCSE may mimic the Heidenhain variant of CJD, particularly by under-recognition of so-called CJD red flags: First, the occurrence of 14-3-3 proteins is known to be positive after either acute stroke or seizures.Secondly, though increased intensity on DWI in CJD is discussed as a noninvasive biomarker, such signal abnormalities – particularly if sparing the basal ganglia – are not specific to CJD. Thirdly, NCSE patients with altered consciousness often present with localized or lateralized sharp waves of triphasic configuration.These atypical triphasic waves are considered to be of epileptic origin if they disappear following antiepileptic drug treatment as in our case ( Trinka and Leitinger, 2015 ).