Automatic EEG interpretation: a new computer-assisted system for the automatic integrative interpretation of awake background EEG.

A new computer-assisted system for automatic interpretation of the awake electroencephalogram (EEG) was developed. First, all the items necessary for EEG interpretation were determined in accordance with the procedure that a qualified electroencephalographer (EEGer) goes through for the visual inspection of the background EEG activity, and then each item was defined quantitatively. For the automatic interpretation, specific EEG parameters were determined for each item so that they could fit the graded judgement of the item by the qualified EEGer as closely as possible. These specific EEG parameters were actually calculated from periodograms obtained from the time series of EEG records of 14 patients with various neurological diseases. The automatic EEG interpretation system thus established was applied to the EEG data of these 14 subjects and to 3 additional EEGs, and the results were compared with those obtained through the visual interpretation by the EEGer. This automatic EEG interpretation was found to be in good agreement with the visual interpretation by the EEGer in most EEG records. In contrast with the previous automatic analyses of EEG which were focussed on certain aspects of EEG such as the dominant rhythm, the present system is unique in its capability of providing an integrative interpretation of the spontaneous awake EEG by taking into account all its features except for paroxysmal abnormalities.     

Pilomotor seizures in mesial temporal lobe epilepsy: a case confirmed by intracranial EEG.

We report the first case in which intracranial EEG was used to confirm pilomotor seizures of mesial temporal origin. A 41-year-old man who had pilomotor seizures in the left arm in addition to complex partial seizures was admitted for presurgical evaluation. Intracranial EEG revealed ictal discharges in the left mesial temporal area during left pilomotor seizures. Moreover, electrical stimulation of the left mesial temporal area induced a habitual pilomotor seizure. After anteromesial temporal lobectomy, the patient became seizure-free. The localizing and lateralizing value of pilomotor seizures are discussed.     

Spontaneous mesencephalic hemorrhage: case report and physiopathological interpretation of its course

We describe a case of spontaneous mesencephalic hemorrhage which evolved in 4 stages with complete clinical resolution. In the light of our findings and of published data we interpret the phenomenon in terms of the regional anatomy and vascularization.

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Sommario Viene descritto un caso di emorragia mesencefalica spontanea ad evoluzione in 4 tempi e con successiva risoluzione completa della sintomatologia clinica. Tenuto conto anche dei dati della letteratura, che depongono per una prognosi benigna della malattia, è stato interpretato il fenomeno sulla base delle caratteristiche della vascolarizzazione e della organizzazione anatomica regionale.

     

Fragile X syndrome confirmed by molecular analysis: a case-control study with pre and post-puberal patients

The fragile X syndrome (FRAXA) is the most common cause of inherited mental retardation. However, it has been frequently underdiagnosed in pediatric population. The characterization of the most significant pre and post-puberal clinical features observed among patients that are positive for the FMR-1 mutation, is useful as a screening tool for ordering the DNA test. Therefore, a screening program for FRAXA has been conducted in a sample of 104 mentally retarded individuals (92 males and 12 females), comprehending familial history and physical examination in order to determine the clinical characteristics. The molecular test for the disease was performed in all individuals. Seventeen patients (14 males) were positive for the FMR-1 mutation. Familial mental retardation and poor eye contact were the most common clinical findings with statistical significance (p<0.05) in FRAXA pre and post-puberal patients. The post-puberal patients presented, as opposed to the control group, large ears, broad forehead and macroorchidism.     

The interpretation of the EEG in stupor and coma

This review discusses a variety of causes of stupor and coma and associated electroencephalographic (EEG) findings. These include metabolic disturbances such as hepatic or renal dysfunction, which are often characterized by slowing of background rhythms and triphasic waves. Hypoxia and drug intoxications can produce a number of abnormal EEG patterns such as burst suppression, alpha coma, and spindle coma. Structural lesions, either supra- or infratentorial, are reviewed. EEGs in the former may show focal disturbances such as delta and theta activity, epileptiform abnormalities, and attenuation of faster frequencies. In infratentorial lesions, the EEG may appear normal, particularly with a pontine lesion. Some patients may be encephalopathic because of ongoing epileptic activity with minimal or no motor movements. This entity, nonconvulsive status epilepticus (NCSE), is difficult to diagnose in obtunded/comatose patients, and an EEG is required to verify the diagnosis and to monitor treatment. Several EEG patterns and their interpretation in suspected cases of NCSE such as periodic lateralized epileptiform discharges (PLEDs), bilateral independent periodic lateralized epileptiform discharges (BIPLEDs), generalized periodic epileptiform discharges (GPEDs), and triphasic waves are reviewed. Other entities discussed include the locked-in syndrome, neocortical death, persistent vegetative state, brainstem death, and brain death.     

Hydrolethalus syndrome: neuropathology of 21 cases confirmed by HYLS1 gene mutation analysis

Hydrolethalus syndrome is a lethal malformation syndrome with a severe brain malformation, most often hydrocephaly and absent midline structures. Other frequent findings are micrognathia, polydactyly, and defective lobation of the lungs. Hydrolethalus syndrome is inherited in an autosomal recessive manner and is caused by a missense mutation in the HYLS1 gene. Here, we report the neuropathologic features of 21 genetically confirmed cases. Typically, 2 separated cerebral hemispheres could be identified, but they lacked midline and olfactory structures and were situated basally with a massive accumulation of cerebrospinal fluid. Temporal and occipital lobes were hypoplastic, and normally developed hippocampi were not found. Primitive thalami and basal ganglia were fused in the midline. A hypothalamic hamartoma was a frequent finding, and brainstem and cerebellum were hypoplastic. Three cases were hydranencephalic, and 1 was anencephalic. A midline "keyhole" defect in the skull base was a constant finding. Histologically, the cortex was dysplastic. This pattern of brain pathology, clearly belonging to the midline patterning defects, seems to be unique for the hydrolethalus syndrome and combines features of disturbed neurulation, prosencephalization, and migration. Despite variation in the clinicopathologic phenotype, all cases in the series carried the same homozygous missense mutation in HYLS1.     

Suppression of complex visual hallucinatory experiences by occipital transcranial magnetic stimulation: a case report

Abstract We report a patient with visual hallucinations and illusions along with an associated visual field defect after bilateral ischemic damage to his occipital visual cortex. These hallucinations were long-standing and of both simple and complex (well-formed) type. Application of low frequency (1 Hz) repetitive Transcranial Magnetic Stimulation (rTMS) to the occipital cortex led to a complete cessation of visual hallucinatory symptoms. The use of TMS to probe the neurophysiology, and possibly alleviate, visual hallucinatory experiences is discussed.     

Temporo-occipital spikes: a typical EEG finding in Kabuki syndrome

Kabuki syndrome is a rare dysmorphogenic disorder. The central nervous system is often involved, and epilepsy is a common symptom. The diagnosis is clinical, and no typical electroencephalographic findings have thus far been reported. We have documented temporo-occipital spikes in sleep electroencephalogram in all our three Kabuki patients. The location of the spikes was similar in all cases although their occurrence varied from continuous spiking to single spikes. We suggest that temporo-occipital spikes are typical in Kabuki syndrome and discuss the possible cause of this finding.     

Saethre-Chotzen syndrome: a clinical,EEG and neuroradiological study

Saethre-Chotzen syndrome is a form of acrocephalosyndactyly with autosomal dominant inheritance, characterized by craniosynostosis, facial asymmetry, palpebral ptosis, deviated nasal septum, partial cutaneous syndactyly, and various skeletal abnormalities. We studied in detail the neurological, EEG, and neuroradiological features of a group of 11 (6 male, 5 female) patients with Saethre-Chotzen syndrome. Four subjects were affected by seizures; they had paroxysmal EEG abnormalities, and gross neuroimaging revealed destructive brain lesions or malformations. Our findings suggest that CNS involvement in Saethre-Chotzen syndrome might be more severe than previously reported and support the wider use of neurophysiological and neuroimaging techniques in the study of children with this syndrome.Presented at the Consensus Conference on Craniosynostoses, Rome, 4–6 May 1995     

A review of the EEG literature on Ganser's syndrome

Ganser's syndrome has been classified as a histrionic disorder, a psychotic illness, a dissociative disorder, a factitious disorder, and an organic illness. The possibility of an underlying organic component to Ganser's syndrome is often implicated. A case which includes CT scan and EEG tests is presented and the EEG data in patients with Ganser's syndrome are reviewed. The majority of EEG data was not suggestive of any specific organic illness.     

Improving the interpretation of ictal scalp EEG: BSS-CCA algorithm for muscle artifact removal

PURPOSE: To investigate the potential clinical relevance of a new algorithm to remove muscle artifacts in ictal scalp EEG. METHODS: Thirty-seven patients with refractory partial epilepsy with a well-defined seizure onset zone based on full presurgical evaluation, including SISCOM but excluding ictal EEG findings, were included. One ictal EEG of each patient was presented to a clinical neurophysiologist who was blinded to all other data. Ictal EEGs were first rated after band-pass filtering, then after elimination of muscle artifacts using a blind source separation-canonical correlation analysis technique (BSS-CCA). Degree of muscle artifact contamination, lateralization, localization, time and pattern of ictal EEG onset were compared between the two readings and validated against the other localizing information. RESULTS: Muscle artifacts contaminated 97% of ictal EEGs, and interfered with the interpretation in 76%, more often in extratemporal than temporal lobe seizures. BSS-CCA significantly improved the sensitivity to localize the seizure onset from 62% to 81%, and performed best in ictal EEGs with moderate to severe muscle artifact contamination. In a significant number of the contaminated EEGs, BSS-CCA also led to an earlier identification of ictal EEG changes, and recognition of ictal EEG patterns that were hidden by muscle artifact. CONCLUSIONS: Muscle artifacts interfered with the interpretation in a majority of ictal EEGs. BSS-CCA reliably removed these muscle artifacts in a user-friendly manner. BSS-CCA may have an important place in the interpretation of ictal EEGs during presurgical evaluation of patients with refractory partial epilepsy.