The aim of this study was to evaluate the clinical utility of arterial spin labeling (ASL) magnetic resonance imaging (MRI) for the detection of cerebellar hypoperfusion in patients with spinocerebellar degeneration (SCD). Regional cerebral blood flow (CBF) were obtained from ASL and I-IMP single-photon emission computed tomography (SPECT) images by volume-of-interest analysis in patients with SCD (n = 16). Regional CBF were also measured by ASL in age-matched controls (n = 19) and by SPECT in separate controls (n = 17). The cerebellar CBF values were normalized to the CBF values for the whole gray matter (nCBF) in ASL and SPECT. The mean cerebellar nCBF measured by ASL was lower in patients with SCD (0.70 ± 0.09) than in the controls (0.91 ± 0.05) (p < 0.001), which was consistent with the comparison using SPECT (0.82 ± 0.05 vs. 0.98 ± 0.05, p < 0.001). The cerebellar nCBF measured by ASL significantly correlated with that determined by SPECT in patients (r = 0.56, p < 0.001). ASL imaging showed decreased cerebellar blood flow, which correlated with that measured by SPECT, in patients with SCD. These findings suggest the clinical utility of noninvasive MRI with ASL for detecting cerebellar hypoperfusion in addition to atrophy, which would aid the diagnosis of SCD.
Several reports have presented patients with subacute cerebellar ataxia (CA) and Lambert-Eaton myasthenic syndrome (LEMS). Some clinical features of those patients have been described in the previous reports, manifestation of subacute CA prior to LEMS or a co-existence of both diseases, a high incidence of malignancy, and less efficacy of the treatment for subacute CA compared with that for LEMS. Cerebellar ataxia in some patients with LEMS has been suggested to be caused by antibodies to P/Q-type voltage-gated calcium channels (VGCCs). We report herein a patient with subacute CA and LEMS. Cerebellar ataxia appeared 15 months after the occurrence of LEMS, and the onset of CA was thought to be due to serum anti-P/Q-type VGCC antibodies. The clinical course of this patient was atypical, as follows: (1) LEMS preceded subacute CA, which developed after intracranial aneurysm surgery, (2) no malignancy was detected when both diseases co-existed, (3) symptoms of LEMS did not progress with the onset of CA, and (4) there was a definite improvement in symptoms of CA and (123)I-IMP SPECT imaging findings after steroid administration. In addition, it is remarkable that LEMS became aggravated in electrophysiologic examinations, in contrast to subacute CA. We suggest that these atypical features of subacute CA and the changes in LEMS may be associated with a balance between the amount of serum anti-P/Q-type VGCC antibodies and the susceptibility of the cerebellum and presynaptic nerve terminals to the antibodies. More cases are needed to investigate the mechanisms involved. The subacute CA and LEMS in this patient have remained comparatively silent after the withdrawal of steroids, and we are continuing to observe her condition.
We report a 63-year-old man who presented with the left facial palsy, the left hemiparesis, the left limb ataxia, and the bilateral truncal ataxia. On admission, magnetic resonance imaging (MRI) showed an abnormal high intensity lesion at the right paramedian region of the upper to middle pons on T2-weighted images (T2WI). He was diagnosed as having a pontine lacunar infarction. The contralateral cerebellar lesions were caused by involvement of the pontocerebellar fibers. On the 29th day from the onset, MRI showed the new abnormal high intensity lesions at the bilateral middle cerebellar peduncles on T2WI. These lesions were supposed to be Wallerian degeneration caused by involvement of the pontocerebellar fibers. This case suggests that Wallerian degeneration occurs followed by a unilateral infarction involving pontocerebellar fibers.
Hashimoto's encephalopathy (HE) presents with a variety of neurologic and neuropsychiatric features. Sixteen percentages of HE patients show cerebellar ataxia as a main neurological feature. The clinical features, treatments, laboratory features, brain images, and serum anti-NH(2)-terminal of α-enolase autoantibodies (anti-NAE Abs), which is a useful diagnostic marker of HE, were investigated in 8 patients. They presented with pure cerebellar ataxia and fulfilled the diagnostic criteria for HE based on the presence of anti-thyroid antibodies and responsiveness to immunotherapy, and were compared with clinical features in other autoimmune cerebellar ataxia associated with anti-GAD, anti-gliadin or anti-Yo. All autoimmune cerebellar ataxic patients presented with truncal ataxia, while nystagmus was absent in HE patients. Most of ataxic form of HE patients had insidious onset mimicking spinocerebellar degeneration, but brain magnetic resonance imaging showed no or mild atrophy of the cerebellum in all patients. Ataxic form of HE patients demonstrated an absence of nystagmus and tended to show a better response to immunotherapy. When a pure cerebellar ataxic patient who presents with truncal ataxia without nystagmus and cerebellar atrophy on brain MRI, HE should be considered as a differential diagnosis and anti-NAE Abs should be examined for the screening of this disease.
To clarify the role of oxidative stress and mitochondrial dysfunction in the pathogenesis of Parkinson's disease (PD) in living patients, positron emission tomography (PET) with [(62)Cu]diacetyl-bis(N(4)-methylthiosemicarbazone) ([(62)Cu]ATSM) was applied to functional imaging of oxidative stress mainly due to mitochondrial dysfunction in the striata of patients with PD. Fifteen PD patients who presented with lateral dominant symptoms at onset and six healthy controls underwent [(62)Cu]ATSM PET. Dynamic PET data acquisition was performed, and standardized uptake values (SUVs) were obtained from the delayed phase of dynamic data by means of region of interest analysis. The striatum-to-cerebellum SUV ratio (S/C ratio) was calculated from the SUV in all subjects of the striatum and the cerebellar cortex. The mean S/C ratio of the bilateral striata of the patients (1.15±0.10) was significantly increased compared with that of the controls (1.08±0.02) (P<.05). In the patients, the S/C ratio of the bilateral striata showed a positive correlation with the Unified Parkinson's Disease Rating Scale (UPDRS) rating (r=0.52, P<.05), and the S/C ratio of the striatum contralateral to the initially affected body side showed a strong positive correlation with the UPDRS rating (r=0.62, P<.05). [(62)Cu]ATSM PET imaging demonstrated that striatal oxidative stress was enhanced in PD patients compared with the controls and increased with the progression of disease severity, particularly in the contralateral striatum. These findings indicated that oxidative stress associates with striatal neurodegeneration in PD.
Crossed cerebellar hyperperfusion (CCH) is detected in patients with epilepsy by brain perfusion studies including single photon emission computed tomography and positron emission tomography. In addition, brain perfusion can be studied with arterial spin labeling (ASL), which is a non-invasive MRI perfusion method that quantitatively measures cerebral blood flow per unit tissue mass. We followed up a 47-year-old patient with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) by continuous arterial spin labeling technique, which showed crossed cerebellar hyperperfusion after acute stroke-like episode. This cerebellar hyperperfusion normalized in the follow-up.
We reported a 61-year-old man who had developed acute cerebellar ataxia in the trunk and the lower limbs. His chemical blood analysis showed very mild hypothyroidism and the presence of serum anti-thyroid peroxidase (TPO) antibody and anti-NH2 terminal of alpha-enolase (NAE) antibody. While cerebellar atrophy was not evident on magnetic resonance imaging (MRI) of the brain, 99mTc-ECD SPECT using the easy Z-score imaging system (eZIS) showed decreased regional cerebral blood flow (rCBF) in the vermis of cerebellum. His cerebellar ataxia improved spontaneously within three weeks. The present case is very rare and suggests that anti-NAE autoantibody may be associated with actue cerebellar ataxia.
This study sought to precisely evaluate striatal oxidative stress and its relationship with the disease severity in Parkinson's disease (PD) using double brain imaging, 62Cu-diacetyl-bis (N4-methylthiosemicarbazone) (62Cu-ATSM) PET and 123I-FP-CIT SPECT. Nine PD patients were studied with brain 62Cu-ATSM PET for oxidative stress and 123I-FP-CIT SPECT for the density of striatal dopamine transporter. Standardized uptake values (SUVs) were obtained from the delayed phase of dynamic 62Cu-ATSM PET, and striatum-to-cerebellum SUV ratio (SUVR) was calculated. To correct the effect of neuronal loss in the striatum, 62Cu-ATSM SUVR was corrected for striatal specific binding ratio (SBR) values of 123I-FP-CIT (SUVR/SBR). 62Cu-ATSM SUVR without correction was not significantly correlated with disease severity estimated by the Unified Parkinson's Disease Rating Scale (UPDRS) scores or 123I-FP-CIT SBR. In contrast, the SUVR/SBR showed significant correlations with the UPDRS total and motor scores, and 123I-FP-CIT SBR. Oxidative stress in the remaining striatal dopaminergic neurons estimated by SUVR/SBR was increased with disease severity in PD patients, suggesting that oxidative stress based on mitochondrial dysfunction contributes to promoting dopaminergic neuronal degeneration in PD. 62Cu-ATSM PET with 123I-FP-CIT SPECT correction would be a promising tool to evaluate dopaminergic neuronal oxidative stress in PD.