Low-Dose Gabapentin in Treatment of High-Altitude Headache

Headache is the most prevalent symptom of acute mountain sickness. We conducted a pilot clinical trial at an altitude of 3500 m to evaluate the efficacy of gabapentin in treatment of high-altitude headache (HAH). Twenty-four adult HAH patients (10 female, 14 male; age 18–50 years) were randomly assigned to receive either 300 mg of gabapentin capsule or identical placebo. After 1 h the presence of HAH and need to receive supplementary analgesic were assessed. The duration of the HAH-free phase after taking additional analgesic was also registered. Four patients in the gabapentin group asked for additional analgesics, whereas nine placebo recipients did not find primary medication satisfactory after the first hour of treatment ( P = 0.04). The mean HAH-free period was 17.10 h in the gabapentin group, which was significantly higher than in the placebo group with a mean of 10.08 h ( P = 0.02). This preliminary observation indicates that gabapentin is effective in treatment and alleviation of HAH.

Respiratory rate within the first hour of ascent predicts subsequent acute mountain sickness severity

BACKGROUND

Altitude illness results from hypobaric hypoxia at altitudes higher than 2500 meters above sea level. To determine whether vital signs can be used as predictors for severe acute mountain sickness, we carried out a prospective observational study.

METHODS

A cohort of 90 individuals (male/female ratio: 2; age: 13 - 65 years) in a mountain hotel's clinic at 3450 meters in Iran were studied from September through October 2006. Demographics and vital signs were measured during the first hour of ascent. The individuals were followed for acute mountain sickness symptoms including headache, dizziness, nausea or vomiting, insomnia, and fatigue. Lake Louise criteria were used to diagnose acute mountain sickness. Severe acute mountain sickness was considered if a score of equal or more than 5 was present. Significance was assigned to values of P<0.05.

RESULTS

Acute mountain sickness was diagnosed in 34 (37.8%) participants after 24 hours of ascent. Severe acute mountain sickness was detected in 14 (15.6%) participants. A respiratory rate of 20 or more during the first hour of ascent was recorded for nine (64.3%) patients with severe acute mountain sickness and 15 (19.7%) individuals in the negative/mild acute mountain sickness group. This suggests an association between early high respiratory rates and risk of subsequent severe acute mountain sickness (P=0.001).

CONCLUSION

There is an association between a rise in the respiratory rate and susceptibility to acute mountain sickness. This can enable us to predict severe acute mountain sickness and prevent it. Furthermore, Tochal Mountain Hotel guests should be aware of the risk of acute mountain sickness and should be recommended to use prophylactic acetazolamide or dexamethasone before ascent.

High-altitude sleep disturbance: Results of the Groningen Sleep Quality Questionnaire survey

OBJECTIVE

To assess the Groningen Sleep Quality Scale (GSQS) for evaluation of high-altitude sleep (HAS) disturbance and employ GSQ questionnaire to describe HAS.

METHODS

After the first night's stay at the altitude of 3500 m, quality of sleep for 100 participants (age: 29.13+/-11.01 years; 36 females/64 males) was assessed using the self-administered 15-item GSQS translated into Farsi.

RESULTS

Mean GSQS score was 5.36+/-4.32; 38 (38%) participants had a score equal to or less than 2, and 46 (46%) participants had a score equal to or more than 6. A Cronbach's alpha of 0.90 was calculated for internal consistency. Waking up several times during the night was the most prevalent complaint during the first night of sleep, and absolute inability to sleep was the most uncommon problem.

CONCLUSIONS

HAS disturbance, which involved many of newcomers to a high altitude, had various harmful effects. For HAS research, GSQS was confirmed to be valid and reliable.

Gabapentin for prevention of hypobaric hypoxia-induced headache: randomized double-blind clinical trial

BACKGROUND

High-altitude headache (HAH) is a hypobaric hypoxia-induced symptom that is commonly experienced by newcomers to high-altitude areas.

OBJECTIVE

To assess the efficacy of gabapentin in the prevention of HAH.

METHODS

A placebo-controlled randomised trial was performed at an altitude of 3500 m. Two hundred and four unacclimatised 15-65-year-old (mean age (+/-SD), 31.5 (SD 11.7)) hotel guests were randomly assigned to a 600 mg single-dose of gabapentin capsule or identical placebo. HAH incidence and intensity were measured to assess gabapentin efficacy. Intention-to-treat analysis was performed.

RESULTS

HAH incidence was not significantly different between subjects under gabapentin (44 (43.1%)) compared with placebo (56 (54.9%); p = 0.09). In contrast, moderate/severe HAH had a lower incidence in the gabapentin group (27 (26.5%)) versus the placebo group (42 (41.2%)), showing that gabapentin reduced HAH attack intensity (p = 0.03).

CONCLUSIONS

Gabapentin was effective for the prevention of HAH and had satisfactory tolerability.

TRIAL REGISTRATION NUMBER

ISRCTN26123577.

Sumatriptan for prevention of acute mountain sickness: randomized clinical trial

OBJECTIVE

To determine the impact of sumatriptan prophylaxis on acute mountain sickness (AMS) and altitude headache development within 24 hours of ascent, we designed a double-blind, randomized, clinical trial.

METHODS

A prospective, double-blind, randomized, placebo-controlled trial was conducted in Tochal Mountain Hotel at an altitude of 3,500 meters above sea level during October 2006 to November 2006. A total of 102 Iranian adults were assigned to receive either sumatriptan succinate (50mg) or placebo within 1 hour of ascent. AMS incidence was measured by Lake Louise AMS score > or = 3 with headache and one other symptom. Secondary outcome measures included severity of syndrome (Lake Louise scores > or = 5), incidence of headache, and severity of headache.

RESULTS

Based on intention-to-treat analysis, AMS was more prevalent in placebo group (n = 23 [45.1%]) than sumatriptan group (n = 12 [23.5%]; p = 0.02). Headache also had a greater rate for placebo users (placebo vs sumatriptan group: 29 [56.9%] vs 17 [33.3%]; p = 0.02). No association was detected between sumatriptan prophylaxis and AMS or altitude headache severity.

DISCUSSION

Sumatriptan prophylaxis is effective to prevent AMS development. Furthermore, our findings confirm cerebral vasodilative and edematous mechanisms of AMS progression, whereas sumatriptan is a selective 5-hydroxytryptamine(1) receptor subtype agonist and a selective cerebral vasoconstrictor as a result (http://www.controlled-trials.com/ISRCTN87201238/).

Striae gravidarum: associated factors

BACKGROUND

Striae gravidarum (SG) is the most common change in connective tissue of pregnant women and may cause cosmetic concerns.

OBJECTIVES

To determine the frequency of SG in Iranian pregnant women and its possible associations with the characteristics of themselves and their newborns.

METHODS

One hundred and eighteen primigravid pregnant women were included in this prospective observational study at their first prenatal visit, among them 114 completed the study and gave birth.

RESULTS

One hundred (87.7%) of 114 women developed SG with a mean Davey's score of 4.04 +/- 2.47. The mean gestational age at which SG first appeared was 27.57 +/- 5.38 weeks. Family history of SG in mother, baseline and delivery body mass index, greatest abdominal and hip girths, newborn weight, height and head circumference were significantly associated with the presence of SG. All of these factors were also correlated with Davey's score.

CONCLUSION

Genetic and physical risk factors may be involved in the development of SG in primigravid women.

Reverse association between high-altitude headache and nasal congestion

No evidence is available to show that nasal congestion is a manifestation of exposing an individual to high altitude and hypoxia. Since both nasal congestion and high-altitude headache are vasogenic, we explored whether there is a coincidence between these two symptoms. A prospective observational study was carried out on a cohort of 118 adults (>18 years old) in a mountain clinic at 3450 m. After 24 h of ascent, an interview was held to ask if each individual experienced acute mountain sickness symptoms (headache, etc.) and nasal congestion. Sixty-six (55.9%) individuals mentioned headache within 24 h after ascent and nasal congestion was reported by 34 (28.8%) individuals. There was a reverse association between headache and nasal congestion (P < 0.001). In conclusion, there is a reverse association between altitude headache and nasal congestion, probably as result of contradictory autoregulation effects or exaggerated sympathetic activity.