Myoclonic encephalopathy due to bismuth salts: treatment with dimercaprol and analysis of CSF transmitters

Two cases of myoclonic encephalopathy due to bismuth salts intoxication are reported. In both, treatment with dimercaprol led to clinical recovery. This therapy was shown to enhance bismuth clearance. We also present data on the CSF metabolites dopamine, norepinephrine and serotonin of one patient.     

Myoclonic encephalopathy due to bismuth following colectomy. Apropos of a case]

Bismuth encephalopathy mainly affects chronic constipation sufferers. The case described, which is practically identical, should be considered (in the absence of constipation) within the context of resection for cancer. The responsibility of bismuth, suggested in five similar cases by Burns and colleagues, is here confirmed by the blood, C.S.F. and urine levels. The mechanism of encephalopathy and the possibility of a failure to eliminate bismuth affecting these levels are discussed.     

Lithium encephalopathy: a clinical, psychiatric, and EEG evaluation

The authors present three cases in which lithium, in combination with a neuroleptic, is implicated in inducing an organic brain syndrome. Subsequent withdrawal of lithium reversed the clinical and EEG picture in the two patients seen in follow-up.     

Surgical treatment of epilepsy due to cortical dysplasia: clinical and EEG findings.

Seventeen patients with cortical dysplasia who had surgical resection for medically intractable partial epilepsy were studied. Compared with two groups of surgically treated patients with intractable epilepsy due to tumour (n = 20) and mesial temporal sclerosis (n = 40), patients with cortical dysplasia showed significantly more frequent extratemporal lesions, more frequent non-epileptiform EEG abnormalities and less favourable surgical outcome for seizure control. Patients with cortical dysplasia were younger at onset of seizures and had a lower detection rate of CT abnormalities compared with the tumour group, and lower IQ compared with the mesial temporal sclerosis group. MRI was abnormal in five of seven patients. Six patients became seizure-free or almost seizure-free but eight did not experience relief of seizures. Surgical outcome related to the extent of pathology but not to the histological abnormality. Lesions outside the temporal and frontal lobes were correlated with poor surgical outcome, as were generalised interictal EEG abnormalities, which may reflect extensive or multiple lesions. Ictal intracranial recordings were not useful for presurgical evaluation of cortical dysplasia.     

Extradural application of bismuth iodoform paraffin paste causing relapsing bismuth encephalopathy: a case report with CT and MRI studies.

Bismuth iodoform paraffin paste (BIPP) is used in dressings in ear, nose, and throat, dental, and neurosurgical practice. Neurotoxicity due to absorption of bismuth from the BIPP pack is rare. It is preventable and reversible but likely to be fatal if unrecognised. A case of relapsing but reversible toxic encephalopathy due to a large extradural BIPP pack is reported in a 57 year old Caucasian woman, operated on for a huge basal cell carcinoma of the vertex invading the skull and extradural space. Clinical, neuroradiological (CT and MRI), and biochemical studies are presented and discussed in the light of the available literature.     

Zonisamide eradicated paroxysmal headache with EEG abnormalities triggered by hypertensive encephalopathy due to purpura nephritic syndrome

Generally, prognosis of hypertensive encephalopathy in childhood is favorable. We reported a 5-year-old girl who presented with a headache attack and EEG abnormalities after hypertensive encephalopathy due to purpura nephritis. The patient had suffered from hypertensive encephalopathy due to purpura nephritis, which soon ameliorated. Five months later, she developed attacks of headache, vomiting and disturbed consciousness with left side-predominant EEG abnormalities. Although carbamazepine and sodium valproate failed to improve her condition, zonisamide eradicated both the symptoms and EEG abnormalities, and an attack has not reoccurred for 5 years since completion of her treatment. It is noteworthy that delayed-onset complications can occur in child hypertensive encephalopathy, cases of which should be followed up prudently. Zonisamide should be considered for treatment of attacks of headaches with an epileptic character.     

Hyperekplexia and trismus due to brainstem encephalopathy

The brainstem is said to be the generator of pathologicalstartle responses due to reticular reflex myoclonus or hyperekplexia. Apatient with facial weakness, nystagmus, and pyramidal tract signs hadgeneralised reflex spasms in response to auditory, visual and tactilestimuli which clinically and neurophysiologically resembledhyperekplexia. The case is unusual because as well as hyperekplexia,the patient's initial presentation was with an equally raremanifestation of brainstem pathology—brainstem mediated trismus. Thecauses of brainstem trismus and exaggerated startle responses arediscussed with respect to their underlying mechanisms.

     

Cefepime-induced encephalopathy: clinical and electroencephalographic features in seven patients

Cefepime, a fourth-generation cephalosporin, with large antibacterial spectrum, is a commonly used antibiotic for the treatment of serious hospital infections. Its security report is considered favourable. Recently, many cases of a severe and reversible cefepime-induced encephalopathy were described. In this paper, we report seven patients with reversible cefepime-induced encephalopathy, with a peculiar EEG pattern, characterized by semiperiodic diffuse triphasic waves. We discuss the EEG abnormalities found and their association with nonconvulsive status epilepticus.     

Clinical and imaging correlates of EEG patterns in hospitalized patients with encephalopathy

To identify the relationship between pathologic electroencephalographic (EEG) patterns, clinical and neuroradiological abnormalities, and outcome in hospitalized patients with acute encephalopathy. This 5-year cohort study was performed at an academic tertiary care center. EEGs in 154 patients with altered mental status were classified according to five predefined patterns: Isolated continuous slowing of background activity (theta, theta/delta, and delta activity) and patterns with slowing background activity with episodic transients [i.e., triphasic waves (TWs) or frontal intermittent delta activity (FIRDA)]. Clinical characteristics, blood tests and neuroimaging were compared among groups. Associations between EEG patterns and structural and non-structural abnormalities were calculated. Glasgow Outcome Score >3 at discharge was defined as favorable and 1–3 as unfavorable outcome. In multivariable analyses, theta was associated with brain atrophy (OR 2.6, p = 0.020), theta/delta with intracerebral hemorrhages (OR 6.8, p = 0.005), FIRDA with past cerebrovascular accidents (OR 2.7, p = 0.004), TWs with liver or multi-organ failure (OR 6, p = 0.004; OR 4, p = 0.039), and delta activity with alcohol/drug abuse with or without intoxication, and HIV infection (OR 3.8, p = 0.003; OR 9, p = 0.004). TWs were associated with death (OR 4.5, p = 0.005); theta/delta with unfavorable outcomes (OR 2.5, p = 0.033), while patients with FIRDA had favorable outcomes (OR 4.8, p = 0.004). In encephalopathic patients, well-defined EEG patterns are associated with specific pathological conditions and outcomes, suggesting that mechanistic hypotheses underlie these abnormal EEG patterns. To clarify the respective contributions of non-structural and structural abnormalities to encephalopathy reflected in specific EEG patterns, prospective studies using continuous EEG monitoring during the acute onset of encephalopathy are needed.     

The EEG in progressive dialysis encephalopathy. The EEG and clinical indices of PDE in cases treated with desferrioxamine

Two patients with progressive dialysis encephalopathy (PDE) were subjected to serial EEG recording and neuropsychological tests in order to assess the value of the investigations as indices of the course of PDE during desferrioxamine treatment. EEG proved unreliable for this purpose.     

Evolution of stimulus-induced rhythmic EEG discharges in three patients with encephalopathy

Stimulus-induced rhythmic EEG discharges (SIRDs) is a recently reported phenomenon in critically ill patients and little is known about their evolution. We found SIRDs in three patients with encephalopathy and followed them with serial EEGs. SIRDs appeared between 4 and 13 days after the onset of illness and persisted for 2–3 days. The discharges were elicited by tactile or nociceptive stimuli and lasted for 20–120 s. They were detected in 2/6, 1/3 and 2/11 EEGs performed between 9 and 32, 2 and 4 and 3 and 15 days, respectively, after the onset of illness. Their morphology varied: blunt triphasic waves, rhythmic delta activity and rhythmic sharp wave complexes. The background EEG activity was slowed or suppressed in all. One patient had acute disseminated encephalomyelitis (ADEM) with good recovery and the other two had fatal hypoxic ischemic encephalopathy. SIRDs appear to be a transient phenomena occurring in patients with encephalopathy, appearing hours to few days after the onset of illness. This is the first report of SIRDs in ADEM. Serial EEGs and repeated testing of EEG response to tactile and nociceptive stimuli is required for their detection. Larger number of patients with SIRDs need to be studied to assess their prognostic significance.     

Extrapyramidal symptoms due to dopamine-blocking agents in patients with AIDS encephalopathy.

OBJECTIVE: The authors attempted to determine whether patients with AIDS are more susceptible to neuroleptic side effects than other patients. METHOD: Retrospective chart review was used to assess the frequency and severity of extrapyramidal symptoms in patients with AIDS and psychotic patients without AIDS who had taken dopamine-blocking agents. The charts of 804 men younger than 50 years were reviewed, and patients were excluded if they had not taken dopamine blockers, had taken them for more than 1 month, had received concomitant antiparkinsonian agents, had focal brain lesions or histories of Parkinson's disease or meningitis, had used cocaine, amphetamines, or opiates within 1 month of admission, or, among the comparison group, had HIV risk factors. For the remaining 31 AIDS and 32 comparison patients, age, duration of dopamine blocker treatment, dose in chlorpromazine equivalents, and nature and severity of parkinsonian complications were recorded. RESULTS: The mean drug dose and body weight were significantly lower in the AIDS group. The likelihood of developing extrapyramidal symptoms was 2.4 times as high among the AIDS patients as among the comparison group. Such symptoms were developed by 50% of the AIDS patients who received less than 4 mg/kg of chlorpromazine equivalents per day and 78% of those who received more than 4 mg/kg per day. CONCLUSIONS: These preliminary results suggest that AIDS patients are more susceptible to extrapyramidal symptoms than psychotic patients without AIDS and that neuroleptics should be used cautiously and in lower doses for patients with AIDS.     

Subacute spongiform encephalopathy with periodic paroxysmal activities: clinical evolution and serial EEG findings in 20 cases

Evolution of both clinical and EEG abnormalities was analyzed in 20 (16 pathologically confirmed) patients suffering from subacute spongiform encephalopathy with periodic paroxysmal activities (PPA) on the EEG. Illness duration was less than 4 and greater than 17 months in 65% and 10% of cases, respectively. All data but EEG were utilized to assess 3 conventional clinical stages in 20 patients. The early clinical stage was characterized by gradual presentation of gait disturbances, mental deterioration, sensory or autonomic disorders. In contrast with other reports, no PPA were observed in 10 EEG recordings from 7 patients examined at the early clinical stage. Both clinical and EEG findings were not in contrast with a hypothetic subcortical onset of disease. Similar to recent data in the literature, early PPA appeared within 12 weeks of disease evolution in 88% of patients who underwent EEG recordings in the first 3 months of disease. Nonetheless, these early PPA always occurred at an intermediary stage, when our patients showed a marked worsening of the clinical picture. Focal, segmental and/or generalized myoclonic jerks were observed in 15%, 53% and 100% of cases at prodromal, intermediary and terminal stages respectively. Different kinds of PPA were observed: bi-tri-phasic periodic complexes (PC), periodic complexes with multiphasic configuration (PPC) and periodic polyspiking discharges (PPD). Abnormal "pacing" of PC by slowly repeated flashes was found in 4 patients presenting visual hallucinations or cortical blindness. Burst-suppression activity was frequently found at the terminal stage in decorticate patients.