An intronic GAA repeat expansion in the FGF14 gene was recently identified as a common cause of autosomal dominant GAA-FGF14 ataxia (SCA27B). We aimed to characterize in detail the clinical and video-oculographic features in our cohort of SCA27B patients. We genotyped the FGF14 GAA repeat expansion in 52 patients with unsolved late-onset cerebellar ataxia. Brain MRI and nerve conduction study, as well as video-oculographic (VOG) assessment, were performed. Eight patients (15.4%) with pathogenic GAA repeat expansion in the FGF14 gene were found. The median age at onset was 51 years (range—23–63 years). Sensory axonal neuropathy was found in 5/8 patients. Cerebellar atrophy was observed in 5/8 patients, and in one case, pontocerebellar atrophy was found. All tested patients had impaired smooth pursuit, 5/6 patients had impaired vestibulo-ocular reflex suppression, nystagmus, and an increased number of square wave jerks, 4/6 patients had horizontal gaze-evoked nystagmus, 3/6 had spontaneous downbeat nystagmus, and 1/6 had an upbeat one. Video head impulse test gain was lower than 0.8 on both sides in 2/4 patients, along with the presence of overt saccades. Further studies in different cohorts are needed to complete the phenotype of the FGF14-related disorders.

We present a case of idiopathic generalized epilepsy (IGE) with seizures manifesting in the context of Graves disease and unusual interictal EEG pattern of bilateral independent 3 Hz spike and wave activity. A 33-year old man with three generalized tonic-clonic seizures (GTCS) in history admitted for overnight video-EEG. At the age of 28, he had his first seizure soon after being diagnosed with Graves' disease. For four years, he received thiamazole and then underwent total thyroidectomy. EEG showed a high number of generalized 3-Hz spike-and-wave discharges (GSWD) but also revealed numerous runs of bitemporal independent lateralized 3-Hz spike-and-wave activity (LSWA). GSWD and LSWA were mostly independent and had slightly different morphology. A diagnosis of IGE with GTCS upon awakening was made. On levetiracetam therapy, the patient demonstrated no seizure recurrence during 2-year follow-up. Repeated overnight EEG showed significant GSWD reduction and complete LSWA suppression. To our knowledge, in patients with IGE, strictly lateralized spike-and-wave activity was never reported. In this case, thyroid dysfunction seemed to increase propensity to generate spontaneous seizures. We speculate that thyroid dysfunction superimposed on IGE thalamocortical network oscillations resulted in uncommon bitemporal independent LSWA.

Creutzfeldt-Jakob disease (CJD) is a devastating degenerative brain disorder caused by an abnormal isoform of a cellular glycoprotein which is known as the prion protein. A diagnosis of CJD is usually based on specific clinical signs, EEG and MRI findings, as well as the presence of the 14–3-3 protein in the cerebrospinal fluid. Although end-stage CJD usually has a typical clinical presentation, early symptoms may be variable. We present an uncommon case of CJD which manifested with primary progressive aphasia, leading to an incorrect diagnosis of frontotemporal dementia. EEG performed eight months after symptom onset revealed focal periodic sharp wave complexes that later evolved into diffuse EEG abnormalities characteristic of CJD. Brain MRI also suggested the diagnosis of CJD. Later, the patient developed rapidly progressive dementia, visual symptoms, ataxia, extrapyramidal symptoms, followed by dysphagia and mutism, and died 34 months after disease onset. PPA is a relatively uncommon first manifestation of CJD, occurring only in about 1% of all CJD cases. Our case is also remarkable because we were able to capture focal periodic sharp wave complexes at the stage of the CJD when aphasia was the only clinical manifestation. We demonstrate that both brain MRI and wake and sleep EEG should be a mandatory part of the diagnostic workup for patients presenting with primary progressive aphasia.

Cefepime is a fourth-generation cephalosporin antibiotic widely used in clinical practice for various organ systems pathology treatment. The article describes the clinical observation of a patient who, 3 days after cefepime administration, had a decrease in the level of consciousness, regarded as encephalopathy. Cefepime-induced neurotoxicity is characterized by toxic encephalopathy, which manifests 2–6 days after the start of the treatment with this drug and disappears 1–3 days after its withdrawal. Electroencephalography (EEG) abnormalities include generalized periodic discharges (GPR) of triphasic morphology or a pattern corresponding to the criteria for non-convulsive status epilepticus (BSES). In our observation, the EEG recorded stimulus-induced GPRs of triphasic morphology with a frequency of 1.5 Hz; a test with intravenous administration of an antiepileptic drug (levetiracetam) was negative. A day after the withdrawal of cefepime, the patient’s level of consciousness returned to the initial level, and on the EEG periodic discharges completely regressed. Thus, cefepime may cause encephalopathy in patients with rhythmic or intermittent EEG activity, especially in the presence of a stimulus-induced component. In some cases, the use of cefepime may develop epileptic seizures and BSES.

Both non-epileptic sleep disturbances and epilepsy are common in patients with mucopolysaccharidoses (MPS), so diagnosis of sleep-related hypermotor epilepsy in these patients is a tackling issue. We present a case of an adult patient with MPS IIIB (Sanfilippo syndrome), who presented with numerous nocturnal events of sudden awakening and hypermotor behavior, which had been previously regarded as parasomnias. Overnight video-EEG captured numerous stereotypical seizures with ictal pattern in the frontal regions, which led the diagnosis of SHE. The patient was started with carbamazepine, which resulted in a substantial reduction in the number of seizures. Our report provides further support for use of overnight video-EEG in the differential diagnosis of sleep-related disorders in MPS, yet true incidence of SHE in MPS patients remains unknown.