Area 5 Influences Excitability within the Primary Motor Cortex in Humans

In non-human primates, Brodmann's area 5 (BA 5) has direct connectivity with primary motor cortex (M1), is largely dedicated to the representation of the hand and may have evolved with the ability to perform skilled hand movement. Less is known about human BA 5 and its interaction with M1 neural circuits related to hand control. The present study examines the influence of BA 5 on excitatory and inhibitory neural circuitry within M1 bilaterally before and after continuous (cTBS), intermittent (iTBS), and sham theta-burst stimulation (sham TBS) over left hemisphere BA 5. Using single and paired-pulse TMS, measurements of motor evoked potentials (MEPs), short interval intracortical inhibition (SICI), and intracortical facilitation (ICF) were quantified for the representation of the first dorsal interosseous muscle. Results indicate that cTBS over BA 5 influences M1 excitability such that MEP amplitudes are increased bilaterally for up to one hour. ITBS over BA 5 results in an increase in MEP amplitude contralateral to stimulation with a delayed onset that persists up to one hour. SICI and ICF were unaltered following TBS over BA 5. Similarly, F-wave amplitude and latency were unaltered following cTBS over BA 5. The data suggest that BA 5 alters M1 output directed to the hand by influencing corticospinal neurons and not interneurons that mediate SICI or ICF circuitry. Targeting BA 5 via cTBS and iTBS is a novel mechanism to powerfully modulate activity within M1 and may provide an avenue for investigating hand control in healthy populations and modifying impaired hand function in clinical populations

Frequency and characteristics of chronic fatigue syndrome in multiple sclerosis patients at a university hospital in Eastern Saudi Arabia

BACKGROUND: Multiple sclerosis (MS) is a chronic, inflammatory demyelinating disease that affects various parts of the central nervous system. Fatigue, a common symptom, transient, prolonged, or chronic experienced by individuals with MS, can significantly impact daily functioning. It can be associated with underlying pathological processes or can have an idiopathic cause, such as chronic fatigue syndrome (CFS). The study aimed to assess the presence and etiology of fatigue in MS patients and its relationship with CFS. MATERIALS AND METHODS: This cross-sectional study was conducted in the Eastern Province of Saudi Arabia. Data were collected using a questionnaire from a sample of 225 MS patients receiving care at our university hospital. The questionnaire included the Centers for Disease Control and Prevention (CDC) criteria for diagnosing CFS and the Expanded Disability Status Scale to evaluate fatigue in MS patients. RESULTS: Of the total of 225 MS patients who participated in this study, 87.1% were diagnosed with relapsing-remitting MS, 6.7% with primary progressive MS, 3.6% with clinically isolated syndrome, and 2.7% with secondary progressive MS. About 53% had experienced fatigue that persisted for over 6 months. Analysis of CFS diagnosis revealed that 7.3% of patients met both CDC criteria and self-reported answers while 17.5% reported having CFS despite not meeting the CDC criteria. These findings highlight a significant lack of agreement between patient-reported diagnoses and established criteria, indicating poor agreement (P = 0.028). CONCLUSION: The study found an association between CFS and MS, and a significant impact on daily functioning. The study revealed lack of agreement between patient-reported diagnoses and established criteria for CFS. This emphasizes the need for a standardized approach to diagnosis and evaluation of fatigue in MS patients

Characteristics and outcomes of large artery occlusion-related stroke due to intracranial atherostenosis: An experience from a single center in Saudi Arabia

BACKGROUND: Literature on the frequency, response to treatment, and outcomes of acute ischemic stroke (AIS) due to intracranial atherostenosis (ICAS)-related intracranial large artery occlusion (ILAO) from Saudi Arabia is scarce. The aim of this study was to identify the percentage, describe the characteristics, and observe the treatment response in patients with AIS attributed to ICAS-related ILAO. MATERIALS AND METHODS: This cross-sectional study included all adult patients from 2017-2021 who fulfilled the inclusion criteria for the diagnosis of ICAS-related AIS. Patients were dichotomized based on ILAO. Mortality and functional outcomes (FOCs) based on 90 days’ dependence level were compared between the two groups. The association between ILAO and other variables was assessed using the Chi-squared test, odds ratios (OR), and 95% confidence interval (CI). RESULTS: ILAO was found in 38.7% of patients with ICAS-related AIS. Men comprised three-fourths of the cohort and were more frequent in the ILAO group. Smoking was associated with increased (P = 0.04) likelihood of ILAO. Patients with ILAO had more severe strokes (P ≤ 0.001) than patients without. Middle cerebral artery was the most common occluded vessel (52%). Functional dependence (P = 0.003, OR = 2.87, CI = 1.42–5.77), malignant transformation (P = 0.001, OR = 8.0, CI = 1.82–35.9), and mortality (P ≤ 0.001, OR = 7.67, CI = 2.40–24.5) were significantly higher among ILAO group. Patients with ILAO with unfavorable FOC were older than those who achieved better FOC (P ≤ 0.001). Thrombolysis (P = 0.02, OR = 2.50, CI = 1.15–5.41) and mechanical thrombectomy (MT) improved FOC in patients with ILAO (P = 0.04, OR = 2.33, CI = 1.10–4.92). CONCLUSION: ILAO is common in patients with ICAS-related AIS. Timely hyperacute stroke treatment can help improve the FOC of otherwise disabling stroke due to ILAO. Raising awareness of the community about stroke is needed, so that a higher number of patients can arrive at hospital within the golden hours. Further data from the region are required to recognize the efficacy of MT in ICAS-related ILAO