Biomedical subjects

Alex Iranzo

Publications and source records attributed to Alex Iranzo.

5 recordsLinked to original sources

PubMed2025

Post-traumatic stress disorder and REM-sleep behavior disorder: exploring genetic associations and causal links.

OBJECTIVE: To explore potential genetic and/or causal associations between Post-Traumatic Stress Disorder and neurodegeneration-related isolated/idiopathic rapid-eye-movement sleep behavior disorder. METHODS: We conducted polygenic risk score, genetic correlation, and Mendelian randomization analyses using the latest genome-wide association studies summary statistics and individual genotyping data. Next, a blinded observer examined dopamine transporter imaging binding status-a marker of neurodegeneration-in patients with isolated/idiopathic rapid-eye movement sleep behavior disorder, with (N = 6) and without Post-Traumatic Stress Disorder (N = 32). RESULTS: Polygenic risk scores for Post-Traumatic Stress Disorder were associated with isolated/idiopathic rapid-eye-movement sleep behavior disorder, with each standard deviation increase linked to 14.7% higher odds (odds ratio = 1.15, 95% confidence interval: 1.04 to 1.26, p = 0.005). However, genetic correlation was weak, and Mendelian randomization did not support a potential causal relationship. The proportion of individuals with abnormal dopamine transporter imaging binding status was significantly higher in the Post-Traumatic Stress Disorder group compared to those without the disorder (p=0.01, X2 = 6.62). INTERPRETATION: Polygenic risk scores analysis identified an association between Post-Traumatic Stress Disorder and neurodegeneration-related isolated/idiopathic rapid-eye-movement sleep behavior disorder, consistent with the result from the small exploratory substudy. The lack of strong genetic correlation or causation may reflect limited sample size. Further research with larger and more diverse cohorts is crucial to clarify the genetic, biological and physiological mechanisms underlying this association.

Journal Article↗

PubMed2003

Decreased hypocretin-1 (Orexin-A) levels in the cerebrospinal fluid of patients with myotonic dystrophy and excessive daytime sleepiness.

STUDY OBJECTIVE: Myotonic dystrophy type 1 is a multisystem disorder with myotonia, muscle weakness, cataracts, endocrine dysfunction, and intellectual impairment. This disorder is caused by a CTG triplet expansion in the 3' untranslated region of the DMPK gene on 19q13. Myotonic dystrophy type 1 is frequently associated with excessive daytime sleepiness, sharing with narcolepsy a short sleep latency and the presence of sleep-onset rapid eye movement periods during the Multiple Sleep Latency Test. Since narcolepsy is characterized by a dysfunction of the hypothalamic hypocretin system, we investigated whether patients with myotonic dystrophy type 1 with excessive daytime sleepiness have abnormalities in the hypocretin system. DESIGN/PARTICIPANTS: Six patients with myotonic dystrophy type 1 complaining of excessive daytime sleepiness and 13 healthy controls without a sleep disorder were included. The patients with myotonic dystrophy type 1 were evaluated using clinical interviews, nocturnal polysomnograms, and Multiple Sleep Latency Tests. All patients had a confirmed genetic diagnosis for DM1 and were HLA typed. Cerebrospinal fluid hypocretin-1 levels were measured using a direct radioimmunoassay in patients and controls. SETTING: University hospital sleep laboratory. INTERVENTIONS: N/A. MEASUREMENT AND RESULTS: The mean sleep latency on Multiple Sleep Latency Tests was abnormal in all patients (< 5 minutes in 2, < or = 8 in 4) and 2 sleep-onset rapid eye movement periods were observed in 2 subjects. All patients were HLA-DQB1*0602 negative. Hypocretin-1 levels were significantly lower in patients versus controls (p < 0.001); 1 case with 2 sleep-onset rapid eye movement periods had hypocretin-1 levels in the range generally observed in narcolepsy (< 110 pg/mL). Three cases had intermediate levels (110-200 pg/mL). Hypocretin-1 levels did not correlate clinically with disease severity or duration or with subjective or objective sleepiness reports. CONCLUSIONS: A dysfunction of the hypothalamic hypocretin system may mediate sleepiness and abnormal Multiple Sleep Latency Test results in patients with myotonic dystrophy type 1.

Adult↗

PubMed2002

[Narcolepsy].

Explore the source record for details and available documents.

Humans↗

PubMed2002

Usefulness of uvulopalatopharyngoplasty with genioglossus and hyoid advancement in the treatment of obstructive sleep apnea.

OBJECTIVE: To evaluate the usefulness of uvulopalatopharyngoplasty plus mandibular osteotomy with genioglossus and hyoid advancement in the treatment of obstructive sleep apnea syndrome (OSAS). DESIGN: Prospective study of 20 consecutive patients with OSAS. SETTING: University medical center. PATIENTS AND INTERVENTIONS: Twenty OSAS patients with multilevel upper airway obstruction who refused continuous positive airway pressure treatment. All patients were evaluated before and 6 months after surgery by clinical history, the Epworth Sleepiness Scale, physical examination, fiberoptic nasopharyngoscopy combined with the Müller maneuver, cephalometric analysis, nocturnal polysomnography, and a second-night polysomnography with upper airway pressure recording during sleep. Surgery procedures were uvulopalatopharyngoplasty plus mandibular osteotomy with genioglossus and hyoid advancement. Surgical successful outcome was defined as an apnea-hypopnea index (AHI) lower than 20 plus subjective resolution of daytime symptoms. MAIN OUTCOME MEASURE: Surgical success rate. RESULTS: Mean +/- SD AHI decreased from 60.5 +/- 16.5 to 44.6 +/- 27(P =.007), and CT90 (percentage of time with oxyhemoglobin saturation below 90%) decreased from 39.5% +/- 26% to 25.1% +/- 26.4% (P =.002). The overall surgical success rate was 35% but increased to 57% in patients with moderate OSAS (AHI, 41-60) and to 100% in mild OSAS (AHI, 21-40). In the group of severe OSAS, the success rate was 9%. Predictors of surgical outcome success were the AHI, CT90, stages 2 and 3-4 sleep percentages, and the cephalometric ANB angle (angle formed from the deepest point on the maxillary outer contour to the nasion to the deepest point on the outer mandibular contour). CONCLUSION: Patients with mild and moderate OSAS and multilevel obstruction in the upper airway may benefit from uvulopalatopharyngoplasty plus genioglossus and hyoid advancement.

Adult↗

PubMed2002

Brainstem proton magnetic resonance spectroscopy in idopathic REM sleep behavior disorder.

STUDY OBJECTIVES: Rapid-eye-movement (REM) sleep behavior disorder (RBD) is thought to result from a dysfunction of the brainstem structures that regulate physiologic REM sleep muscle atonia. Proton magnetic resonance spectroscopy (1H-MRS) is a noninvasive method that allows detection of in vivo neuronal dysfunction in localized brain areas. The aim of our study was to investigate whether 1H-MRS can detect brainstem abnormalities in patients with idiopathic RBD. DESIGN: 1H-MRS centered on the midbrain and the pontine tegmentum was acquired in 15 patients with idiopathic RBD and 15 control subjects matched for age and sex. SETTING: University hospital sleep laboratory center. PARTICIPANTS: Fifteen untreated patients with chronic RBD diagnosed by history and video-polysomnography, normal neurologic examination, and normal cranial MRI. Fifteen healthy controls with no sleep complaints and normal polysomnography and brain MRI. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: The metabolic peaks detectable with 1H-MRS, N-acetylaspartate (NAA), creatine-phosphocreatine (Cr), choline-containing compounds (Cho) and myoinositol (mI), and the ratios of NAA, Cho and ml to Cr were evaluated both in the midbrain and pontine tegmentum. No significant differences in N-acetylaspartate/creatine, choline/creatine and myoinosito/creatine ratios were found between patients and controls. CONCLUSIONS: The results do not suggest that marked mesopontine neuronal loss or 1H-MRS detectable metabolic disturbances occur in idiopathic RBD.

Aged↗