Imaging findings after methanol intoxication (cohort of 46 patients).

OBJECTIVES: Our goal is to demonstrate the variability of imaging findings, primarily in the MRI, in 46 patients who survived acute methanol poisoning. This cohort of patients is the largest such sample group examined by MRI. METHODS: Patients were examined by means of imaging methods (42 patients by MRI and 4 by CT). All had an identical protocol of MR examination (T2WI, FLAIR, T1WI with or without application of contrast medium and T2WI/FFE, DWI in the transversal plane of the scan, and with focus on the optic nerves in the coronal plane of the scan in T2WI-SPIR). RESULTS: Imaging methods revealed a positive finding associated with methanol intoxication in 21 patients (46%). These consisted of symmetrical lesions in the putamen--13 patients (28%), haemorrhage--13 cases (28%), deposits in white matter with localization primarily subcortically--4 cases (9%), lesions in the region of the globus pallidus--7 cases (15%) (in 6 cases without combination with the lesions in the putamen), lesions in the brainstem afflicted 6 patients (13%), and lesion in the cerebellum was found in one case. A pathological finding was found only in the patients examined by MRI. CONCLUSION: Almost half of the patients who survived acute methanol poisoning had pathological findings by MRI. The most common finding concerned an affliction of the putamen, which is a predilection area. An interesting finding was the relatively frequent occurrence of selective lesion of the globus pallidus, which is more usually associated with other types of intoxication.

Gait and Balance Impairment after Acute Methanol Poisoning.

Neurological sequelae including gait impairment were reported in survivors after methanol intoxication; however, no systematic study has been published so far. We aimed to analyse gait and balance impairment in a group of Czech methanol poisoning survivors. We examined 43 patients (age 46 ± 13 years) 2-8 months after methanol poisoning and 43 healthy controls. Investigations contained a shortened version of Falls Efficacy Scale (FES), clinical tests of gait and balance including Timed Up and Go test (TUG) and gait analysis using GaitRite® system, neurological and neuropsychological examination, brain imaging, EMG and tests of alcohol consumption. Nineteen patients admitted balance and gait impairment according to FES. Mild to moderate parkinsonian signs showed seven patients. Patients were slower (8.8 versus 5.7 s, p < 0.001) and performed more steps (11.1 versus 7.9, p < 0.001) in TUG compared with the controls. Gait analysis revealed shorter step length (76.5 versus 88.7 cm, p < 0.001), increased double support phase (18.8 versus 15.5%, p < 0.001) and wider base of support (11.3 versus 9.6 cm, p = 0.006) in patients. Eleven patients had deficit of executive function and performed higher cadence compared to the patients with normal execution (122.7 versus 115.0 step/min., p = 0.025). Lower limb polyneuropathy was verified in nine patients, without relation with gait or balance parameters. Neuroimaging revealed lesions mainly in the basal ganglia. Methanol poisoning survivors presented slower wide-based gait with shortened steps corresponding with frontal gait disorder. Higher stepping cadence associated with executive deficit supported the evidence of frontal lobe dysfunction related to impairment of basal ganglia and connections in frontal cortico-basal ganglia loops.