OBJECTIVETo study the MRI-based characteristics of acute carbon monoxide poisoning (ACOP) and delayed encephalopathy after acute carbon monoxide poisoning (DECAMP), and to compare the degree of brain damage.

METHODSA retrospective analysis was performed on the clinical and MRI data of 27 patients diagnosed with ACOP and 35 patients diagnosed with DECAMP. Ten healthy volunteers were recruited in the normal control group. All subjects received both routine MRI and diffusion-weighted MRI. Apparent diffusion coefficient (ADC) was determined with symmetric measurement of region of interest in the bilateral globus pallidus, white matter around lateral ventricle, and centrum semiovale. ADC values were compared afterwards.

RESULTSThirteen of the 27 ACOP cases were found of symmetrical abnormal signal in the bilateral globus pallidus, among whom 8 patients only showed pallidum region involvement, while the other 5 patients showed involvement of other regions. Eight ACOP patients showed cortical and subcortical white matter involvement, and 4 cases showed diffused abnormal signal around the bilateral ventricles and in the bilateral centrum semiovale. Two cases of ACOP presented with multiple region involvement. Thirty-five DECAMP patients showed diffused swelling and symmetric demyelination in multiple regions of the brain parenchyma. The periventricular white matter and centrum semiovale were involved in 33 cases, the deep brain nuclei were involved in 23 cases, and the cerebral cortex was involved in 3 cases. The ACOP and DECAMP groups had significantly lower ADC values in the periventricular white matter and bilateral centrum semiovale than the normal control group (P < 0.05), and the ADC values were significantly lower in the DECAMP group than in the ACOP group (P < 0.05). The ACOP group had a significantly lower ADC value in the globus pallidus than the DECAMP group and normal control group (P < 0.05); the DECAMP group had a significantly higher ADC value in the globus pallidus than the ACOP group and normal control group (P < 0.05).

CONCLUSIONRoutine MRI and ADC value can evaluate the degree of brain damage in ACOP and DECAMP patients based on lesion involvement on a more microscopic scale. It can provide valuable information for therapy selection and prognostic evaluation.

Adult ; Aged ; Brain Diseases ; chemically induced ; diagnosis ; Carbon Monoxide Poisoning ; complications ; diagnosis ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Retrospective Studies ; Young Adult

Metronidazole is a 5-nitroimidazole compound known as an antimicrobial agent widely used for the treatment of protozoal infection, anaerobic infection, Helicobacter pylori infection and hepatic encephalopathy. It may produce a number of neurologic side effects including peripheral neuropathy, seizure, encephalopathy, ataxic gait and dysarthritic speech. There have been ten or more reports of metronidazole-induced encephalopathy in the literatures including a few reports of brain imaging changes by magnetic resonance images (MRI). However, none of the case of metronidazole-induced encephalopathy in patients with hepatic encephalopathy has been reported yet. Recently, we experienced two cases of metronidazole-induced encephalopathy in patients with liver cirrhosis caused by chronic hepatitis B, which were diagnosed by brain MRI and MR spectroscopy. In this report, we present 2 cases of metronidazole-induced encephalopathy with MR imaging and MR spectroscopic changes including follow- up imaging performed after the discontinuation of the metronidazole with a review of the literatures.
Anti-Infective Agents/*adverse effects ; Brain Diseases/*chemically induced/diagnosis ; English Abstract ; Female ; Humans ; Magnetic Resonance Imaging ; Magnetic Resonance Spectroscopy ; Male ; Metronidazole/*adverse effects ; Middle Aged

Two cats were presented with vestibular signs and seizures. Both cats were diagnosed with thiamine deficiency. The transverse and dorsal T2-weighted magnetic resonance (MR) images revealed the presence of bilateral hyperintense lesions at specific nuclei of the midbrain, cerebellum, and brainstem. After thiamine supplementation, the clinical signs gradually improved. Repeated MR images taken 3 weeks after thiamine supplementation had started showed that the lesions were nearly resolved. This case report describes the clinical and MR findings associated with thiamine deficiency in two cats.
Animals ; Brain Stem/pathology ; Cat Diseases/chemically induced/*diagnosis/*drug therapy ; Cats ; Cerebellum/pathology ; Diet/veterinary ; Dietary Supplements/analysis ; Female ; Magnetic Resonance Imaging/veterinary ; Male ; Mesencephalon/pathology ; Seizures/chemically induced/pathology/veterinary ; Thiamine/administration & dosage/*therapeutic use ; Thiamine Deficiency/chemically induced/diagnosis/drug therapy/*veterinary ; Treatment Outcome

OBJECTIVETo investigate clinical and imaging characteristics of delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) and their relationship to the prognosis.

METHODSThe clinical, CT and MRI findings in 46 patients with DEACMP were analysed and compared.

RESULTSThe main manifestations of the disease were mental and extrapyramidal impairment. CT scan showed diffuse low density changes in bilateral cerebral white matter, bilateral or unilateral globus pallidus or basal ganglia areas. The MRI showed necrosis and degeneration of glodus pallidus and cerebral white matter demyelination mainly around the ventricles, with high signal intensity in T(2)-weighted and equal or low signal intensity in T(1)-weighted as well as the lesions in hippocampus and brain stem. There was the sign of encephalatrophy in the late stage. The positive detectable rate of MRI was 82.1%, higher than that of CT, 43.2%. MRI was more sensitive than CT.

CONCLUSIONThe prognosis of the patients is closely related with the age, time of come after DEACMP and the effectiveness of treatment. Both CT and MRI are valuable in the diagnosis and evaluation of the prognosis for DEACMP. MRI is more sensitive than CT in the diagnosis of DEACMP.

Acute Disease ; Adult ; Aged ; Brain ; diagnostic imaging ; pathology ; Brain Diseases ; chemically induced ; diagnosis ; diagnostic imaging ; Carbon Monoxide Poisoning ; complications ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Prognosis ; Sensitivity and Specificity ; Tomography, X-Ray Computed

Encephalopathy is a disorder characterized by altered brain function, which can be attributed to various causes. Encephalopathy associated with metronidazole administration occurs rarely and depends on the cumulative metronidazole dose, and most patients with this condition recover rapidly after discontinuation of therapy. Because metronidazole is metabolized in the liver and can be transported by the cerebrospinal fluid and cross the blood-brain barrier, it may induce encephalopathy even at a low cumulative dose in patients with hepatic dysfunction. We experienced a patient who showed ataxic gait and dysarthric speech after receiving metronidazole for the treatment of hepatic encephalopathy that was not controlled by the administration of lactulose. The patient was diagnosed as metronidazole-induced encephalopathy, and stopping drug administration resulted in a complete recovery from encephalopathy. This case shows that caution should be exercised when administering metronidazole because even a low dose can induce encephalopathy in patients with liver cirrhosis.
Anti-Infective Agents/*adverse effects/therapeutic use ; Brain Diseases/*chemically induced/diagnosis ; Hepatic Encephalopathy/*drug therapy/etiology ; Humans ; Liver Cirrhosis/*complications ; Magnetic Resonance Imaging ; Male ; Metronidazole/*adverse effects/therapeutic use ; Middle Aged ; Tomography, X-Ray Computed