No abstract

Progressive ataxia and palatal tremor (PAPT) is a rare distinct clinical entity characterized by symptomatic palatal tremor associated with progressive ataxia 1,2 . Few cases have been described in literature, and MRI findings show, in most cases, cerebellar atrophy and bilateral olivary hypertrophy with signal change 1 . We report a case where MRI study at 3T demonstrated marked bilateral olivary complex hyperintensity at T1, with magnetization transfer contrast pulse (MTC) sequence, which was subtle at conventional T2 and FLAIR sequences at 1,5 and 3 T. CASEA 54-year-old male patient presented with a 10-year history of predominantly truncal ataxia manifested mainly by difficulty in climbing stairs with associated oscillopsia and spontaneous nystagmus with closed eyes. He showed significant gait instability on heel-to-toe test and also a 2Hz palatal tremor. Familial history of ataxia was negative , as well as genetic tests for spinocerebellar ataxia 1, 2, 3 and 7. Routine blood analysis, thyroid-stimulating hormone, vitamin B12 and antinuclear antibodies were normal.MRI examinations at 1,5 and 3,0 T showed only moderate cerebellar atrophy and subtle signal change in olivary nuclei on conventional FSE T1, T2 and FLAIR sequences, which were overlooked at the first report. Additional images on 3 T using FSE T1-weighted with magnetization transfer pulse (TR1000, TE 20) showed marked signal alteration of olivary complexes (Figure). DISCUSSIONProgressive ataxia and palatal tremor (PAPT) is a rare disorder more commonly found as a sporadic condition with no identifiable cause. Most cases manifest as slowly progressing ataxia, that can be associated with visual changes, dysarthria and dysphagia 1,2 . Typical MRI abnormalities are cerebellar atrophy, hypertrophy and hyperintensity at T2-weighted and proton density sequences at olivary complexes. The main differential diagnosis of sporadic PAPT is hypertrophic olivary degeneration, a

The basilar artery herniation into the sphenoid sinus secondary to skull base fracture is a rare condition. There have been few cases described worldwide. This entity carries a potential risk of basilar artery stenosis or occlusion, resulting in ischaemia and infarction of the brainstem and cerebellum. Images study such as computed tomography (CT) and MRI plays a crucial role in diagnosing this condition. We report a rare case that shows entrapment of the basilar artery into the sphenoid sinus, after a traumatic skull base fracture, without infarction of the brainstem and cerebellum, with CSF fistula.

PurposeTo find a radiographic method that best correlates with the mean subaxial cervical space available for the cord (MSCSAC) by using a fixed size parameter as radiographic reference, in contrast to the use of vertebral bodies as reference in the mean subaxial cervical Torg ratio (MTorg).MethodsThe study was approved by an institutional review board and written informed consent was obtained. Radiographs and cervical neck MRI were obtained from 18 male rugby athletes (age 18–30 years). Rheumatic disease, symptomatic cervical orthopaedic disease and previous cervical injury were used as exclusion criteria. MSCSAC and MTorg were calculated for each individual as the space available for the cord and Torg ratio averages from C3 to C6, respectively. A new radiographic method, using a metal bar as a size parameter (the corrected diameter of the cervical canal - CDCC), was also calculated for each individual, as well as its average from C3 to C6 (mean corrected diameter of the cervical canal - MCDCC). Values obtained for MCDCC and MTorg were correlated with those obtained by the MSCSAC using Pearson’s coefficient.ResultsFour volunteers were excluded due to previous cervical injury. In total, 14 subjects had their radiographs and MRIs analysed. Pearson’s correlation between MSCSAC and MTorg was 0.5706 (p=0.033). The correlation between MSCSAC and MCDCC was 0.6903 (p=0.006).ConclusionMCDCC correlates better than MTorg with MSCSAC and may be a better radiographic option than MTorg for cervical stenosis evaluation.