ABSTRACT
Hyperechogenicity of the substantia nigra (SN) detected by transcranial sonography is a typical finding in more than 90% of patients with Parkinson's disease (PD) but may also be visible in about 9% of healthy adults. In this study, we found a correlation between SN hyperechogenicity and subtle motor dysfunction in otherwise healthy young tap dancers. In accordance with former findings, results of the present study confirm the hypothesis that SN hyperechogenicity is a marker for a possible functional impairment of the nigrostriatal system, that may become evident under challenging conditions.
Subject(s)
Dancing , Motor Skills Disorders/diagnostic imaging , Motor Skills Disorders/physiopathology , Substantia Nigra/diagnostic imaging , Adult , Case-Control Studies , Female , Humans , Male , Ultrasonography, Doppler, Transcranial/methodsABSTRACT
Increased echogenicity of the substantia nigra (SN) on ultrasound is a typical sonographic finding in Parkinson's disease (PD). Sonographic signal intensity of the SN is related to tissue iron content with higher iron level being associated with increased echogenicity. Recent findings indicate that hyperechogenicity of the SN represents an important susceptibility factor for nigrostriatal degeneration. In this study we determined the prevalence of a characteristic ultrasound sign of Parkinson's disease in first-degree relatives of PD patients. Fourteen patients with sporadic PD and 58 of their relatives underwent neurological, neuropsychological, and ultrasound examination. In addition, four pairs of relatives (one member of each pair exhibiting increased echogenicity of the SN and the other with regular SN echogenicity) underwent (18)F-Dopa PET examination. On transcranial sonography, 26 of the 58 relatives exhibited SN hyperechogenicity. Twenty-four relatives showed minor signs of motor slowing. Relatives with SN hyperechogenicity more often showed signs of hypokinesia (16 v 8 relatives; U test, P = 0.01) and impaired executive functions (Tower of London task, problems solved with the minimum number of moves; U test, P = 0.012) than relatives without this echo pattern. In addition, (18)F-Dopa uptake (influx constants) at the putamen was reduced in subjects with SN hyperechogenicity compared to their relatives without this ultrasound sign (Wilcoxon, P = 0.03). In conclusion, approximately 45% of relatives of PD patients exhibited an increased echogenicity of the SN. This sign is associated with clinical findings and objective measurements, indicating some degree of impaired nigrostriatal function.
Subject(s)
Genetic Predisposition to Disease/genetics , Parkinson Disease/genetics , Substantia Nigra/diagnostic imaging , Tomography, Emission-Computed , Ultrasonography, Doppler, Transcranial , Adult , Dihydroxyphenylalanine , Dominance, Cerebral/physiology , Female , Fluorine Radioisotopes , Genetic Testing , Humans , Male , Middle Aged , Nerve Degeneration/diagnostic imaging , Nerve Degeneration/genetics , Neuropsychological Tests , Parkinson Disease/diagnostic imaging , Problem Solving/physiologyABSTRACT
Conventional duplex sonography is a well-established method for the assessment of the brain-supplying arteries in acute stroke. However, ultrasound (US) remains inconclusive in a significant number of stroke patients. Recently, two new US parameters, the cerebral transit time (cTT) and the global cerebral blood flow volume (CBF), have been introduced. In the present study, we investigated the diagnostic and prognostic value of both parameters in stroke patients. Conventional duplex examinations of the extra- and intracranial brain-supplying arteries and measurement of cTT and CBF were performed in 50 consecutive stroke patients within 24 h after symptom onset and compared with US findings in 22 age-matched healthy controls. Neurological deficits and the degree of disability were graded using several stroke scores, and were re-evaluated for outcome measure after 1 year. CBF and cTT were not assessable in 26% and 20% of the patients, respectively. Compared with the healthy control group, stroke patients showed a significant reduction of CBF and prolongation of cTT. More than 50% of patients with otherwise normal routine duplex examination had abnormal CBF or cTT findings. Furthermore, there was a strong correlation between the reduction of global CBF and the outcome after 1 year. Sonographic assessment of the CBF and cTT are additional parameters that might increase the diagnostic sensitivity of US in stroke patients, and may have prognostic relevance.
