Transcranial Sonography in Ataxia

Transcranial Sonography Characteristics of Cerebellar Neurodegenerative Ataxias

Cerebellar neurodegenerative ataxias are a group of disorders affecting the cerebellum and its pathways with different neurological structures. Transcranial sonography (TCS) has been used for the evaluation of brain parenchymal structures in various diseases because of its fast and safe utilization, especially in neuropsychiatric and neurodegenerative diseases. The aim of our study was to investigate TCS characteristics of patients with neurodegenerative cerebellar ataxias. In our study, we included 74 patients with cerebellar degenerative ataxia; 36.5% had autosomal dominant onset, while 33.8% had sporadic onset. Standardized ultrasonographic planes were used for the identification of brain structures of interest. The SARA, INAS, neuropsychological and psychiatric scales were used for the further clinical evaluation of our study participants. The brainstem raphe was discontinued in 33.8% of the patients. The substantia nigra (SN) hyperechogenicity was identified in 79.7%. The third and fourth ventricle enlargement had 79.7% and 45.9% of patients, respectively. A positive and statistically significant correlation was found between SN hyperechogenicity with dystonia (p < 0.01), rigidity and dyskinesia (p < 0.05). The higher SARA total score is statistically significantly correlated with the larger diameter of the III (r = 0.373; p = 0.001) and IV ventricles (r = 0.324; p = 0.005). In such patients, the echogenicity of substantia nigra has been linked to extrapyramidal signs, and raphe discontinuity to depression. Furthermore, ataxia and its clinical subtypes have positively correlated with the IV ventricle diameter, indicating brain atrophy and brain mass reduction.

Sonographic hypoechogenicity of brainstem raphe nucleus is correlated with electroencephalographic spike frequency in patients with epilepsy

BACKGROUND

Brainstem raphe nucleus (BRN) hypoechogenicity in transcranial sonography (TCS) has been demonstrated in patients with major depression, possibly representing a sonographic manifestation of serotonergic dysfunction in depression. Most patients with epilepsy with comorbid depression exhibit hypoechogenic BRN in TCS. However, the role of BRN in the pathogenesis of epilepsy is unclear. This study aimed to evaluate the correlation of BRN echogenicity with epilepsy itself, and the echogenicity of other midbrain structures and the size of lateral ventricle (LV) will also be evaluated in patients with epilepsy.

METHODS

Thirty-six patients with epilepsy without depression and 37 healthy controls were recruited. Sonographic echogenicity of BRN, caudate nucleus (CN), lentiform nucleus (LN), substantia nigra (SN), and the width of frontal horns of the lateral ventricles (LV) and the third ventricle (TV) were evaluated with TCS. The frequency of interictal epileptiform discharges (IEDs) was assessed with ambulatory electroencephalogram (AEEG).

RESULTS

Hypoechogenicity of BRN was depicted in 36.1% of patients with epilepsy and 18.9% of controls, showing no significant difference. Patients with epilepsy with BRN hypoechogenicity had higher epileptic discharge index (EDI) than those with normal BRN echogenecity. Especially, higher EDI in patients with BRN hypoechogenicity was observed during the sleep period but not during awake period. The width of TV was significantly larger in patients with epilepsy than that in controls. We did not find any difference between patients with epilepsy and controls in the echogenicity of CN, LN, and SN, as well as in the width of frontal horn of LV.

CONCLUSIONS

Hypoechogenic BRN is correlated with a high frequency of epileptic discharges in electroencephalogram (EEG), especially during sleep period but not during awake period, indicating that BRN alterations may play a potential role in the pathogenesis of epilepsy in association with sleep cycle.

Transcranial Sonography Findings in Depression in Association With Psychiatric and Neurologic Diseases: A Review

The transcranial sonography (TCS) finding of reduced echogenicity of brainstem raphe (hypoechogenic BR) has been associated with depressive states. Here, we review the TCS studies in subjects with depressive disorders and with depression related to degenerative brain diseases, and compare the frequency and clinical correlates of hypoechogenic BR in these reports. Summarizing the data published so far, hypoechogenic BR is present in 67% (range, 37-95%) of depressed but only in 15% (5-36%) of nondepressed subjects without history of neurodegenerative disease. The finding of hypoechogenic BR in these subjects is associated with a relative risk of 3.03 (95% CI, 2.44-3.75; P < .001) of being diagnosed with depression. In patients with Parkinson's disease, hypoechogenic BR is present in 63% (35-92%) of depressed but only in 27% (10-62%) of nondepressed patients, resulting in a relative risk of 2.18 (95% CI, 1.80-2.66; P < .001) of being diagnosed with depression. Hypoechogenic BR is associated with depression in a number of neurological disorders such Huntington's disease, idiopathic Rapid Eye Movement (REM) sleep behavior disorder, myotonic dystrophies, and cerebral small vessel disease. Although some studies did not show any relationship between BR echogenicity and severity of depression, others suggest an association with higher severity of depression, or even with suicidal ideation. In one study BR hypoechogenicity was found to be associated with better responsivity to serotonin reuptake inhibitors. Further studies are warranted to compare the TCS findings of BR alteration with post-mortem histopathological findings, and with genetic variants related to cerebral serotonin metabolism.

Hypoechogenicity of brainstem raphe nuclei is associated with increased attack frequency in episodic migraine

INTRODUCTION

Reduced echogenicity of the brainstem raphe nuclei (BRN) was demonstrated in major depression, possibly indicating serotonergic dysfunction. Postulating that migraine may constitute a "chronic low serotonin syndrome," we aimed to evaluate the echogenicity of midbrain structures, including serotonergic BRN in episodic migraine.

METHODS

Transcranial sonography was performed in 39 patients with episodic migraine (median age 35, interquartile range (IQR): 27-47 years; 27 women) and 35 controls (median age 31, IQR: 29-47 years; 19 women). Individuals with concomitant depression were excluded. Echogenicity of BRN, substantia nigra (SN) and third ventricle width was evaluated according to an internationally established examination protocol.

RESULTS

Hypoechogenicity of BRN was depicted in 23.1% of migraine patients and 20% of controls, showing no significant difference. Migraine patients with hypoechogenic BRN had significantly higher attack frequency (median 3, IQR 2-5 vs. 1.5, IQR 1-2 days/month; p = 0.029) and a trend toward earlier disease manifestation. The rate of hyperechogenic SN and width of the third ventricle were similar between both groups. We did not observe any differences between migraine patients with and without aura.

CONCLUSION

Sonographic findings did not differ between migraine patients and controls. Hypoechogenic BRN correlated to a higher migraine attack frequency, probably indicating more severe disease activity.

Substantia nigra echogenicity in hereditary ataxias with and without nigrostriatal pathology: a pilot study

Our objective was to determine whether substantia nigra (SN) hyperechogenicity is greater in spinocerebellar ataxias (SCA) with nigrostriatal affectation than in ataxias without it. A cross-sectional case-control study analyzing four groups of patients was conducted: 1) nigrostriatal ataxias (SCA3 and SCA6), 2) nigrostriatal healthy controls matched by age and sex, 3) non-nigrostriatal ataxias (FRDA and SCA7), and 4) non-nigrostriatal healthy controls matched by age and sex. All the patients underwent a transcranial ultrasound performed by an experienced sonographer blinded to the clinical, genetic, and neuroimaging data. The SN area was measured and compared in the four groups. The SN area was also correlated with clinical features and genetic data in the two ataxia groups. We examined 12 patients with nigrostriatal ataxia (11 SCA3 and 1 SCA6), 12 nigrostriatal healthy control patients, 7 patients with non-nigrostriatal ataxia (5 FRDA and 2 SCA7), and 7 non-nigrostriatal healthy control patients. The median (IQR) SN area (cm(2)) was greater in the nigrostriatal ataxias compared with the controls (right SN, 0.43 [0.44] vs. 0.11 [0.25]; P=0.001; left SN, 0.32 [0.25] vs. 0.11 [0.16]; P=0.001), but was similar among the non-nigrostriatal ataxias and controls. There were no statistically significant differences in the SN area between the nigrostriatal and non-nigrostriatal ataxias, although there was a tendency for a greater left SN area in the nigrostriatal compared with the non-nigrostriatal ataxias (0.32 [0.25] vs. 0.16 [0.24], P=0.083). SN echogenicity is markedly greater in ataxias with nigrostriatal pathology than in controls. The role of SN hyperechogenicity in differentiating ataxias with and without nigrostriatal pathology should be elucidated in future studies.

Transcranial brain parenchymal sonography in neurodegenerative and psychiatric diseases

Transcranial sonography is a highly sensitive noninvasive sonographic method for detection of early and specific echogenic changes in basal ganglia of patients with some neurodegenerative diseases. Transcranial sonography showed substantia nigra hyperechogenicity as a typical echo feature in idiopathic Parkinson disease and lenticular nucleus hyperechogenicity as a characteristic finding in atypical parkinsonian syndromes. Brain stem raphe hypoechogenicity or interruption has been shown to be highly prevalent in patients with unipolar depression as well as depression associated with certain neurodegenerative diseases. Transcranial sonography also revealed basal ganglia hyperechoic changes in movement disorders with trace metal accumulation such as Wilson disease, some entities of neurodegeneration with brain iron accumulation, as well as several forms of spinocerebellar ataxia. Transcranial sonography is a valuable neuro imaging method for early and differential diagnosis and follow-up of patients with neurodegenerative and psychiatric diseases.

Evaluation of CNS involvement in myotonic dystrophy type 1 and type 2 by transcranial sonography

Myotonic dystrophies (DMs) are clinically similar but distinct multisystemic diseases related to different repeat expansion mutations. CNS involvement is one important aspect of both, myotonic dystrophy type 1 and type 2 (DM1, DM2). Transcran ial sonography (TCS) has become a reliable diagnostic tool in the evaluation of several CNS disorders. The aim of this study was to evaluate TCS-findings in DM-patients in correlation with their clinical status. Thirty-one DM-patients (DM1 = 17; DM2 = 14) were examined clinically and sonographically by independent physicians. Echogenicities of basal ganglia and mesencephalic regions were assessed according to the examination protocol for extrapyramidal disorders using a Toshiba Aplio(®) XG ultrasound system. TCS abnormalities were correlated to clinical findings and secondly compared to 31 controls. Ventricle diameters were additionally compared to 3T-MRI volumetry. Nine patients (29 %) showed hyperechogenicity of substantia nigra. Mesencephalic raphe was hypoechogenic in nine (29 %) DM-patients and was more frequently in DM1 patients (p = 0.021). Width of third ventricle was significantly larger in the patient group (p = 0.021) and correlated with MRI-based volumetry (R (2) = 0.756). Pathological raphe signal was observed mainly in patients suffering from daytime sleepiness (sensitivity = 42.1 %, specificity = 88.9 %, p = 0,044), while alterations did not correlate with symptoms of depression. As a novel finding, a relation between mesencephalic raphe echogenicity and excessive daytime sleepiness could be identified in our DM-patients. An alteration of serotonergic raphe structures might be involved in the pathogenesis of hypersomnia in DM. TCS allows for measurement of third ventricle enlargement as a feasible bedside test.

EFNS/MDS-ES/ENS [corrected] recommendations for the diagnosis of Parkinson's disease

BACKGROUND

A Task Force was convened by the EFNS/MDS-ES Scientist Panel on Parkinson's disease (PD) and other movement disorders to systemically review relevant publications on the diagnosis of PD.

METHODS

Following the EFNS instruction for the preparation of neurological diagnostic guidelines, recommendation levels have been generated for diagnostic criteria and investigations.

RESULTS

For the clinical diagnosis, we recommend the use of the Queen Square Brain Bank criteria (Level B). Genetic testing for specific mutations is recommended on an individual basis (Level B), taking into account specific features (i.e. family history and age of onset). We recommend olfactory testing to differentiate PD from other parkinsonian disorders including recessive forms (Level A). Screening for pre-motor PD with olfactory testing requires additional tests due to limited specificity. Drug challenge tests are not recommended for the diagnosis in de novo parkinsonian patients. There is an insufficient evidence to support their role in the differential diagnosis between PD and other parkinsonian syndromes. We recommend an assessment of cognition and a screening for REM sleep behaviour disorder, psychotic manifestations and severe depression in the initial evaluation of suspected PD cases (Level A). Transcranial sonography is recommended for the differentiation of PD from atypical and secondary parkinsonian disorders (Level A), for the early diagnosis of PD and in the detection of subjects at risk for PD (Level A), although the technique is so far not universally used and requires some expertise. Because specificity of TCS for the development of PD is limited, TCS should be used in conjunction with other screening tests. Conventional magnetic resonance imaging and diffusion-weighted imaging at 1.5 T are recommended as neuroimaging tools that can support a diagnosis of multiple system atrophy (MSA) or progressive supranuclear palsy versus PD on the basis of regional atrophy and signal change as well as diffusivity patterns (Level A). DaTscan SPECT is registered in Europe and the United States for the differential diagnosis between degenerative parkinsonisms and essential tremor (Level A). More specifically, DaTscan is indicated in the presence of significant diagnostic uncertainty such as parkinsonism associated with neuroleptic exposure and atypical tremor manifestations such as isolated unilateral postural tremor. Studies of [(123) I]MIBG/SPECT cardiac uptake may be used to identify patients with PD versus controls and MSA patients (Level A). All other SPECT imaging studies do not fulfil registration standards and cannot be recommended for routine clinical use. At the moment, no conclusion can be drawn as to diagnostic efficacy of autonomic function tests, neurophysiological tests and positron emission tomography imaging in PD.

CONCLUSIONS

The diagnosis of PD is still largely based on the correct identification of its clinical features. Selected investigations (genetic, olfactory, and neuroimaging studies) have an ancillary role in confirming the diagnosis, and some of them could be possibly used in the near future to identify subjects in a pre-symptomatic phase of the disease.

Computational prediction of the polyQ and CAG repeat spinocerebellar ataxia network based on sequence identity to untranslated regions

Computational prediction of biological networks would be a tremendous asset to systems biology and personalized medicine. In this paper, we use a moving window bioinformatic screen to identify transcripts with partial identity to the 5' and 3'UTRs of the polyQ spinocerebellar ataxia (SCA) genes ATXN1, ATXN2, ATXN3, ATXN7, TBP and CACNA1A and the CAG repeat expansion gene PPP2R2B. We find that the bioinformatic screen enriches for transcripts that encode proteins that interact and that have functions relevant to polyQ SCA. Transcription control and RNA binding are the primary functional groups represented in the proteins from the combined screens. The insulin growth factor pathway, the WNT pathway, long term potentiation, melanogenesis and ATM mediated DNA repair pathways were identified as important pathways. UGUUU repeats were identified as an abundant motif in the SCA network and PAXIP1, CELF2, CREBBP, EBF1, PLEKHG4, SRSF4, C5orf42, NFIA, STK24, and YWHAG were identified as statistically significant proteins in the polyQ and PPP2R2B network.

Transcranial sonography findings in spinocerebellar ataxia type 3 (Machado-Joseph disease): a cross-sectional study

Few studies on transcranial brain sonography have been performed in hereditary and non-hereditary ataxias. The objective of the present study was to report transcranial brain sonography findings in a sample of clinically and molecularly proven Machado-Joseph disease patients and to compare these data against those of an age- and gender-matched control group. A cross-sectional study on transcranial brain sonography was conducted in 30 Machado-Joseph disease patients. Transcranial brain sonography was performed by an experienced sonographer blinded to the clinical, genetic, and neuroimaging data. The results were compared with those of a control group of 44 healthy subjects matched for age and gender. The sonographic findings were also correlated with clinical features and genetic data in Machado-Joseph disease group. A significantly higher frequency of substantia nigra and lenticular nucleus hyperechogenicity was found in the Machado-Joseph disease group compared to an age- and gender-matched healthy control group (p<0.001). The substantia nigra echogenic area proved to be the best predictor for differentiating cases from controls. Third and lateral ventricles were significantly larger in the Machado-Joseph disease patients than in the control subjects. No significant correlations were found between transcranial brain sonography findings and Machado-Joseph disease demographic/clinical data. Transcranial brain sonography findings in Machado-Joseph disease patients differed significantly to those in age- and gender-matched controls. Substantia nigra hyperechogenicity occurred frequently in Machado-Joseph disease patients and was found to be the best predictor for differentiating cases from controls. Additionally, this data describes the occurrence of brain atrophy in Machado-Joseph disease group.

Transcranial sonography reveals cerebellar, nigral, and forebrain abnormalities in Friedreich's ataxia

BACKGROUND

Friedreich's ataxia (FA) is essentially characterized by degeneration of the dorsal root ganglia, the dorsal nuclei of Clarke, and the long spinal fiber tracts, yet there is accumulating evidence that neurodegeneration extends beyond these predilection sites. Transcranial sonography (TCS) has evolved as a valuable complementary neuroimaging tool in the assessment of neurodegenerative diseases due to its capacity to well depict structural changes and the accumulation of heavy metals. Its use for assessing cerebellar neurodegeneration, however, has not yet been investigated.Here we investigated whether TCS allows to assess particular features of cerebellar as well as midbrain and forebrain abnormalities in FA.

METHODS

Comprehensive TCS imaging of 34 FA patients and 34 age-matched healthy controls.

RESULTS

Hyperechogenicity of the dentate nucleus was very frequent in FA patients (85%) and could even be observed in patients with short disease duration, suggesting that dentate alterations are a common and probably early feature of FA. Substantia nigra was significantly hypoechogenic, possibly indicating regional changes in subcellular brain iron regulation. FA patients showed significantly enlarged 4th, 3rd, and lateral ventricles, thus corroborating earlier MRI and postmortem findings of substantial cerebellar and forebrain atrophy in FA.

CONCLUSIONS

TCS provides a quick-to-apply and inexpensive in vivo assessment of both cerebellar and noncerebellar abnormalities in FA, in particular highlighting dentate hyperechogenicity as a core feature. It might serve as a promising tool for imaging aspects of cerebellar neurodegeneration also in other neurodegenerative disorders.