1/4. Possible valacyclovir-related neurotoxicity and aseptic meningitis.OBJECTIVE: To report a case of neurotoxicity and aseptic meningitis in a patient receiving valacyclovir.CASE SUMMARY: An 86-year-old white man had started valacyclovir 1 g 3 times a day for a herpetic rash along the left side of his face. He subsequently presented with balance difficulties, constant frontal headaches, and a seizure 1 day prior to admission. Cerebral spinal fluid (CSF) analysis revealed 162 white cells/mm(3), 1 red blood cell/mm(3), glucose 56 mg/dL, and protein 144 mg/dL, with a negative Gram stain. Further laboratory examination failed to demonstrate other causes for the patient's clinical picture. After discontinuation of valacyclovir and supportive care, the patient symptomatically improved.DISCUSSION: As of the third week of September 2003, only 1 other case of valacyclovir-related aseptic meningitis was published describing a patient with characteristics similar to those of our patient. Our patient's neurologic symptoms may have been due to acyclovir toxicity, but acyclovir-toxic patients present with normal CSF findings. Several drug classes, including nonsteroidal antiinflammatory drugs, antibiotics, and intravenous immunoglobulins, can induce aseptic meningitis. Other reasons for the patient's symptoms or causes of meningitis were excluded, although viral meningitis remains a possibility. Valacyclovir-induced aseptic meningitis was considered to be possible according to the Naranjo probability scale.CONCLUSIONS: Healthcare providers should be aware of valacyclovir as a possible cause of drug-induced aseptic meningitis.- - - - - - - - - - ranking = 1keywords = probability (Clic here for more details about this article) |
2/4. Acute inhalant-induced neurotoxicity with delayed recovery.OBJECTIVE: To report a case of neurotoxicity and subsequent hospitalization due to abuse of an ethyl chloride inhalant. CASE SUMMARY: A 41-year-old African American male presented to the emergency department due to mental status changes and an inability to walk. After the blood alcohol and urine drug screen returned negative, a family member revealed that the patient frequently abused an inhalant containing the volatile solvent ethyl chloride. DISCUSSION: inhalant abuse is common and is facilitated by the widespread availability of volatile solvents that have legitimate commercial or household uses. Most inhalants are central nervous system depressants and are highly lipophilic. Maximum Impact, which contains ethyl chloride, is sold in stores and is readily available over the internet. While the product has a legitimate use as a VCR head cleaner, it is often illicitly marketed over the internet as a means of getting a "rush" or "high" and for enhancing sexual pleasure. Neurologic symptoms have been reported after deliberate inhalational exposure to ethyl chloride, and 2 deaths have been associated with its use. An objective causality assessment using the Naranjo probability scale revealed a probable adverse drug event. CONCLUSIONS: Inhalants should be included in the differential diagnosis of patients presenting with acute mental status changes and neurologic impairment that resolve over less than one week.- - - - - - - - - - ranking = 1keywords = probability (Clic here for more details about this article) |
3/4. The firing probability of single motor units following transcranial magnetic stimulation in healthy subjects and patients with neurological disease.Magnetic stimuli applied to the scalp can cause single motor units (MUs) to discharge in intrinsic hand or more proximal arm muscles. MUs are much more likely to be fired by stimuli if they are being activated voluntarily at the same time. The changes in firing probability induced by magnetic stimuli in such tonically active MUs have been studied in healthy subjects and patients using peri-stimulus time histograms (PeSTHs). The mean firing level in the 250 msec before the stimulus, was used to define 2 peaks of increased firing after the stimulus. The first, termed the primary peak (PP), was always present, had an onset latency in first dorsal interosseous (FDI) muscle of 20-31 msec and was short in duration (mean 4.9 msec). A second increase in firing probability, the secondary peak (SP), was present in about half the FDI MUs studied, had a mean peak latency of 81.5 msec and had a duration up to about 40 msec. PP often consisted of a number of sub-peaks with intermodal intervals of around 1.5 msec. It is believed that PP is the result of activation of corticospinal (CS) fibres making monosynaptic connections and that sub-peaks within PP are due to the arrival at the motoneuron of successive CS impulses produced by the stimulus. SP is probably due to operation of other excitatory inputs to the motoneuron. In patients, a number of different abnormalities have been identified. PP has been found to be normal, absent, delayed and dispersed or having abnormally separated sub-peaks. Clearly the technique is a powerful tool for dissecting abnormalities in CS projections at the synaptic level.- - - - - - - - - - ranking = 6keywords = probability (Clic here for more details about this article) |
4/4. Neurotoxic complications of contrast computed tomography in children.Four children with brain tumors had marked alterations in levels of consciousness and vital signs after contrast-enhanced cranial computed tomography (CT). Each had clinical evidence of increased intracranial pressure but was alert and coherent before CT. During the procedure, 2 to 2.5 mL/kg 60% diatrizoate meglumine was administered intravenously, and within hours the patients became progressively lethargic and disoriented and bradycardia and hypertension developed; two had generalized seizures. Two children died immediately after the CT procedure. Contrast-enhanced CT may produce grave neurologic complications in children with brain tumors, and this study should be reserved for those patients in whom the probability of obtaining additional information is high. Use of low-osmolality agents or nonionic contrast agents may decrease the morbidity and mortality associated with the procedure.- - - - - - - - - - ranking = 1keywords = probability (Clic here for more details about this article) |