Clinical and Radiological Characteristics Associated with Respiratory Failure in Unilateral Lateral Medullary Infarction.

BACKGROUND: The prognosis for unilateral lateral medullary infarction (ULMI) is generally good but may be aggravated by respiratory failure with fatal outcome. Respiratory failure has been reported in patients with severe bulbar dysfunction and large rostral medullary lesions, but its associated factors have not been systematically studied. We aimed to assess clinical and radiological characteristics associated with respiratory failure in patients with pure acute ULMI. MATERIALS AND METHODS: Seventy-one patients (median age 55 years, 59 males) with MRI-confirmed acute pure ULMI were studied retrospectively. Clinical characteristics were assessed and bulbar symptoms were scored using a scale developed for this study. MRI lesions were classified into 4 groups based on their vertical extent (localized/extensive) and the involvement of the open and/or closed medulla. Clinical characteristics, bulbar scores and MRI lesion characteristics were compared between patients with and without respiratory failure. RESULTS: Respiratory failure occurred in 8(11%) patients. All patients with respiratory failure were male (p = 0.336), had extensive lesions involving the open medulla (p = 0.061), progression of bulbar symptoms (p=0.002) and aspiration pneumonia (p < 0.001). Peak bulbar score (OR, 7.9 [95% CI, 2.3-160.0]; p < 0.001) and older age (OR, 1.2 [95%CI, 1.0-1.6]; p=0.006) were independently associated with respiratory failure. CONCLUSIONS: Extensive damage involving the open/rostral medulla, clinically presenting with severe bulbar dysfunction, in conjunction with factors such as aspiration pneumonia and older age appears to be crucial for the development of respiratory failure in pure ULMI. Further prospective studies are needed to identify other potential risk factors, pathophysiology, and effective preventive measures for respiratory failure in these patients.

Breathing patterns in relation to sleep stages in acute unilateral lateral medullary infarction: An exploratory study.

Our aim was to perform an exploratory study of various irregular breathing patterns (IBPs) across different sleep stages in patients with acute unilateral lateral medullary infarction (ULMI) and compare them to apparently healthy individuals. Polysomnography (PSG) was analyzed for IBPs, such as periodic breathing, ataxic breathing and tachypnea. IBPs were found in 52 % of healthy and 90 % of ULMI subjects (p = 0.001) and occurred in long (≥ 10 min) episodes in 8% of healthy and 68 % of ULMI (p < 0.001). In healthy subjects, short (< 10 min) episodes of mild to moderate ataxic breathing were observed in wakefulness and light sleep and short episodes of periodic breathing upon sleep onset. In ULMI, the most common IBPs were ataxic and periodic breathing (80 % of patients), followed by shallow tachypnea (28 %). Ataxic breathing predominated in wakefulness, ataxic or periodic breathing in light sleep, while breathing tended to normalize in deep and REM sleep. Considering the IBPs occurring in the healthy group as physiological, probably pathological breathing patterns (tachypnea, long episodes of moderate/severe ataxic or long episodes of periodic breathing) occurred in 67 % of ULMI patients. Our findings suggest that ULMI might exacerbate physiological sleep-stage-dependent breathing pattern irregularities, such as ataxic and periodic breathing, in terms of intensity and duration or might even induce non-physiological IBP, such as shallow tachypnea with sustained hypoxia.

Prospective study of sleep-disordered breathing in 28 patients with acute unilateral lateral medullary infarction.

OBJECTIVE: Acute unilateral lateral medullary infarction (ULMI) is complicated by respiratory failure in 2-6% of patients. However, studies investigating milder respiratory disorders not leading to overt respiratory failure, i.e., sleep-disordered breathing (SDB) and its outcome, are lacking. The aim of our study was to identify and prospectively follow SDB in acute ULMI. METHODS: We prospectively followed 28 patients with MRI-confirmed acute ULMI. Polysomnography (PSG) was performed 1-3 times in the acute phase (at 1-4, 5-10, and 14-21 days after onset of symptoms) and after 3-6 months. PSG recordings in the acute phase were analyzed and compared to the follow-up. RESULTS: Apnea-hypopnea index (AHI) ≥ 5/h, AHI ≥ 15/h, and AHI ≥ 30/h in the acute phase were observed in 22 (79%), 19 (68%), and 10 (36%) patients, respectively. CSA, OSA, mixed CSA/OSA, or multiple interchanging SDB types were observed in the acute phase in 12 (43%), 2 (7%), 2 (7%), and 6 (21%) patients, respectively. Peak AHI varied in individual patients (median at 7 (3-14) days after onset). At follow-up, AHI and central AHI tended to decrease (p = 0.007, p = 0.003, respectively), obstructive AHI did not change (p = 0.396). Sleep architecture partially improved with significantly higher percentage of N2 and lower percentage of wakefulness after sleep onset (p = 0.007, p = 0.012, respectively). CONCLUSIONS: Our data show that SDB, particularly CSA, is common in the acute phase of ULMI and that the frequency of central events decreases in the subacute phase. Further studies are needed to clarify the clinical significance and possible treatment options of SDB in these patients.

Short-term impact of fampridine on motor and cognitive functions, mood and quality of life among multiple sclerosis patients.

OBJECTIVE: Previous studies have predominantly investigated the effect of fampridine on lower extremities motor functions while data on its impact on other symptoms of multiple sclerosis (MS) are scarce. The aim of our study was to assess the impact of fampridine on walking, arm/hand function, fatigue, cognitive function, mood and quality of life among responders. METHODS: Our prospective non-randomized study included 30 patients with different types of MS, aged 35-70, EDSS value 3.5-6.5. They were treated with 10mg of fampridine twice daily. The examinations were performed before the treatment, after 14 days, when responders were defined by T25FW (Timed 25-Foot Walk) and 2-min walk test (2MWT) was performed, and after 28 days of treatment, when only the responders were examined. Standardized protocols and questionnaires were used to evaluate the impact of fampridine on walking speed (T25FW, 2MWT), arm/hand function (9-HPT - Nine-Hole Peg Test), cognitive function (PASAT - Paced Auditory Serial Addition Test), total MSFC score (Multiple Sclerosis Functional Composite), fatigue (MFIS - Modified Fatigue Impact Scale), mood (BDI - Beck Depression Inventory) and quality of life (EQ-5D index, EQ-VAS - Euro Quality of Life - 5 Dimension questionnaire and visual analogue scale) in responders. RESULTS: Response rate was 56.7%. Average improvement of T25FW and 2MWT after 14 days of treatment in responders was 3.6s (34.5%) and 37.4m (42.3%), respectively. This improvement persisted after 28 days of treatment. In non-responders there was no significant improvement of T25FW after 14 days (p=0.689), but there was improvement of 2MWT for 13.4m (14.3%) (p=0.000). After 28 days of treatment significant improvement among responders occurred in total MSFC score (p=0.001), 9-HPT (p=0.002), BDI (p=0.005), MFIS total score (p=0.003), physical (p=0.001), cognitive (p=0.008) MFIS subscales, and EQ-5D index (p=0.012). There were implied trends towards improvement in EQ-VAS and psychosocial MFIS subscale, yet not significant (p=0.057 and p=0.127, respectively). There was no statistically significant improvement of PASAT (p=0.432). CONCLUSIONS: The results of our study highlight the potential of fampridine for improving not only walking speed but also arm/hand function, physical and cognitive fatigue, mood and quality of life. There was no objective improvement of cognitive function. Further placebo-controlled studies will be needed for precise definition of fampridine's action beyond its impact on walking.