Dopamine transporter SPECT imaging in Parkinson’s disease and parkinsonian disorders

The dopamine transporter (DAT) imaging provides an objective tool for the assessment of dopaminergic function of presynaptic terminals which is valuable for the differential diagnosis of parkinsonian disorders related to a striatal dopaminergic deficiency from movement disorders not related a striatal dopaminergic deficiency. DAT imaging with single-photon emission computed tomography (SPECT) can be used to confirm or exclude a diagnosis of dopamine deficient parkinsonism in cases where the diagnosis is unclear. It can also detect the dopaminergic dysfunction in presymptomatic subjects at risk for Parkinson’s disease (PD) since the reduced radiotracer binding to DATs in striatum is already present in the prodromal stage of PD. This review covers the rationale of using DAT SPECT imaging in the diagnosis of PD and other parkinsonian disorders, specifically focusing on the practical aspects of imaging and routine clinical indications.

The Complex Genetic Landscape of Hereditary Ataxias in Turkey and Implications in Clinical Practice

BACKGROUND

The genetic and epidemiological features of hereditary ataxias have been reported in several populations; however, Turkey is still unexplored. Due to high consanguinity, recessive ataxias are more common in Turkey than in Western European populations.

OBJECTIVE

To identify the prevalence and genetic structure of hereditary ataxias in the Turkish population.

METHODS

Our cohort consisted of 1296 index cases and 324 affected family members. Polymerase chain reaction followed by Sanger sequencing or fragment analysis were performed to screen for the trinucleotide repeat expansions in families with a dominant inheritance pattern, as well as in sporadic cases. The expansion in the frataxin (FXN) gene was tested in all autosomal recessive cases and in sporadic cases with a compatible phenotype. Whole-exome sequencing was applied to 251 probands, selected based on the family history, age of onset, and phenotype.

RESULTS

Mutations in known ataxia genes were identified in 30% of 1296 probands. Friedreich's ataxia was found to be the most common recessive ataxia in Turkey, followed by autosomal recessive spastic ataxia of Charlevoix-Saguenay. Spinocerebellar ataxia types 2 and 1 were the most common dominant ataxias. Whole-exome sequencing was performed in 251 probands with an approximate diagnostic yield of 50%. Forty-eight novel variants were found in a plethora of genes, suggesting a high heterogeneity. Variants of unknown significance were discussed in light of clinical data.

CONCLUSION

With the large sample size recruited across the country, we consider that our results provide an accurate picture of the frequency of hereditary ataxias in Turkey. © 2021 International Parkinson and Movement Disorder Society.

Multicenter study of levodopa carbidopa intestinal gel in Parkinson’s disease: the Turkish experience

Background/aim

Our purpose was to determine the efficacy of levodopa carbidopa intestinal gel (LCIG) in a series of Turkish patients with Parkinson’s disease (PD).

Materials and methods

We had telephone calls with 54 patients from 11 neurology centers who were on LCIG treatment, and 44 patients or their caregivers were included in an eight-item survey between September 2015 and June 2016. The reliability and validity of the survey were evaluated with intraclass correlation coefficients for every question separately.

Results

Average age of the patients were 63.48 and the duration of PD was 12.79 years. Average LCIG treatment period was 15.63 months. Percentages of the patients who reported they were ‘better’ after LCIG treatment were as follows: 80% for time spent off, 55% for dyskinesia, 65% for tremor, 85% for gait disorder, 50% for pain, 50% for sleep disorders, 42.5% for depression, 32.5% for incontinence, and 70% for activities of daily living. Cronbach’s alpha was 0.795 and the intraclass correlation coefficient was reliable for the items.

Conclusion

As detected by a survey performed by telephone calls with good interrater reliability, patients with PD improve with LCIG treatment in many aspects of the disease.

Effects of different percentages of body weight-supported treadmill training in Parkinson’s disease: a double-blind randomized controlled trial

Background/aim

Body weight-supported treadmill training (BWSTT) might have greater effects than conventional treadmill training (TT) in neurological diseases such as Parkinson’s disease (PD). The aim of this study was to evaluate the effects of different percentages of BWSTT on gait, balance, quality of life, and fatigue in PD.

Materials and methods

Thirty-five patients with moderate to advanced PD were randomized into three BWSTT groups according to the supported percentage of body weight: 0% BWSTT (control group; unsupported TT), 10% BWSTT, or 20% BWSTT. Five patients were excluded due to early discharge and 30 patients completed BWSTT sessions lasting 30 min, 5 days a week, for 6 weeks during their inpatient rehabilitation stay. The primary outcome was 6-min walk distance (6MWD). Secondary outcomes were Unified Parkinson’s Disease Rating Scale (UPDRS), Berg Balance Scale (BBS), Nottingham Health Profile (NHP), Fatigue Impact Scale, and Fatigue Severity Scale scores. Measurements were performed before and after the training.

Results

The unsupported TT group demonstrated no significant improvement in the outcome measures after a 6-week training except for BBS and NHP emotional subscores. Moreover, the NHP pain subscore increased in the unsupported TT group after training. The 10% and 20% supported BWSTT groups demonstrated significant improvements in 6MWD (P = 0.004 and P < 0.001, respectively), UPDRS - motor score (P = 0.012 and P = 0.005, respectively), NHP pain subscore (P = 0.003 and P = 0.002, respectively), and fatigue (P = 0.005 for both) after training. The 20% BWSTT provided the highest improvement in balance among the three groups (P < 0.001) and greater relief of fatigue than 10% BWSTT (P = 0.002).

Conclusion

Six weeks of BWSTT improved walking distance and balance ability, relieved fatigue, and additionally reduced pain in patients with moderate to advanced PD.

Autonomic nervous system dysfunction and serum levels of neurotoxic and neurotrophic cytokines in patients with cobalamin deficiency

OBJECTIVE

The imbalance between neurotoxic cytokine tumor necrosis factor-α (TNF-α) and neurotrophic cytokines epidermal growth factor (EGF) and interleukin-6 (IL-6) plays a role in the pathogenesis of cobalamin (Cbl) deficiency-induced neuropathy. The aim of this study was to evaluate autonomic nervous system dysfunction and to look for any relationship between autonomic nervous system disturbances and serum cytokine levels (TNF-α, EGF, IL-6) in patients with Cbl deficiency.

METHODS

Serum levels of TNF-α, EGF and IL-6 were studied in patients with Cbl deficiency (n=41) and a healthy control group (n=17) and after 3 months in patients who underwent Cbl replacement therapy (n=22). All patients with Cbl deficiency underwent electrophysiological studies (EPS) for the diagnosis of neuropathy. Statistical analysis was performed using SPSS for Windows 11.5 software.

RESULTS

With EPS, 29 of 41 Cbl-deficient patients (70.73%) demonstrated neurological dysfunction [3 (7.32%), 19 (46.34%) and 7 (17.07%) patients with sensorimotor peripheral neuropathy, parasympathetic, and sympathetic autonomic dysfunction, respectively]. Although there was no significant difference in serum levels of EGF and IL-6 between patients with versus without autonomic dysfunction, levels were significantly lower in Cbl- deficient patients than healthy controls.

CONCLUSION

Presence of autonomic dysfunction seems to be a frequent neurological finding in patients with Cbl deficiency. However, we could not find any relationship between serum cytokine levels and autonomic dysfunction by EPS.

Accessory Nerve Function in Lateral Selective Neck Dissection with Undissected Level IIB

BACKGROUND

To investigate the accessory nerve function in lateral selective neck dissections (LSND) performed in laryngeal squamous cell carcinoma patients without dissection of level IIB.

METHODS

Fifteen LSND were performed in 11 N0 laryngeal carcinoma patients with preservation of level IIB. Distal latencies, compound muscle action potentials (CMAP), and electromyography findings were investigated before surgery, during the 3rd postoperative week, and 3 months thereafter to compare the effects of the procedure on the accessory nerve.

RESULTS

Distal latencies and CMAP values were significantly lower in the early and late postoperative periods when compared with preoperative values. In 8 patients, there was no motor unit potential (MUP) in the early postoperative period. However, in the late postoperative period, there was no MUP loss.

CONCLUSIONS

Only temporary functional deterioration of the accessory nerve was seen in patients in whom LSND was performed with undissected level IIB.

Detection of EEG background abnormalities in epilepsy by a new spectral index

OBJECTIVE

In epileptic disorders, EEG background activity is disorganized in or near the epileptogenic focus and spectral EEG analysis (SEA) can provide useful information about the focus. We tried to develop a new spectral index from basic spectral parameters to detect the epileptic abnormalities at EEG background activity.

METHODS

A new spectral EEG index, epileptic abnormality index (EAI), was constructed from frequency band power and power asymmetry parameters. Within the index, parameters were weighted due to both conventional EEG knowledge and their power in discrimination healthy subjects from patients. EEG background activity from 99 epileptic patients and 146 healthy subjects was examined both by EAI and by a conventional SEA method, by using z-scoring statistic. Each test results were compared with visual EEG interpretation of subjects.

RESULTS

In patient groups, EAI was most successful in lateralization of epileptic abnormalities. It was also helpful in discrimination of epileptic patients from normals in the case where visual EEG interpretation was 'normal'.

CONCLUSIONS

EAI depends on basic spectral parameters and it combines statistical methods and clinical knowledge about EEG. It increases the analysis capacity of SEA in evaluation of EEG background activity.

SIGNIFICANCE

EAI is a new and useful approach in detection of EEG background abnormalities in epilepsy and its logical base can also be used in the detection of brain electrical activity abnormalities other than epileptic disorders.

Brain SPECT evaluation of patients with pure photosensitive epilepsy

This study was performed to determine the utility of 99mTc-HMPAO brain SPECT in evaluating patients with pure photosensitive epilepsy.

METHODS

Seven patients (2 boys, 5 girls), aged 8 to 15 yr (mean 11.1 +/- 2.5 yr), were studied. All patients underwent a detailed neurologic examination, interictal and ictal EEGs, CT and/or MRI and SPECT imaging. The baseline SPECT study was performed during the interictal period and the activation study was performed while the patients were having seizures provoked by watching television.

RESULTS

The baseline SPECT study showed that six of seven patients had relatively hypoperfused regions in their frontal lobes that could involve the neighboring parietal and temporal regions. The activation study revealed that all seven patients had relative hyperperfusion in these brain regions that were relatively hypoperfused in the baseline study. The side-to-side asymmetry indexes for these visually-interpreted rCBF abnormalities ranged from 3% to 6%.

CONCLUSION

The relatively consistent pattern of frontal rCBF alterations suggests that frontal lobe functions were implicated in the evolution of photosensitivity-related seizures in patients with pure photosensitive epilepsy.