Hemodynamic and Thermal Responses to Head and Neck Cooling in Men and Women1

Abstract

Personal cooling systems are used to alleviate symptoms of multiple sclerosis and to prevent increased core temperature during daily activities. The objective of this study was to determine the operating characteristics and the physiologic changes produced by short term use of one commercially available thermal control system. A Life Support Systems, Inc. Mark VII portable cooling system and a liquid cooling helmet were used to cool the head and neck regions of 12 female and 12 male subjects (25-55 yr) in this study. The healthy subjects, seated in an upright position at normal room temperature (approximately 21 degrees C), were tested for 30 min with the liquid cooling garment operated at its maximum cooling capacity. Electrocardiograms and scalp and intracranial blood flows were recorded periodically during each test sequence. Scalp, right and left ear, and oral temperatures and cooling system parameters were logged every 5 min. Scalp, right and left ear canal, and oral temperatures were all significantly (P <0.05) reduced by 30 min of head and neck cooling. Oral temperatures decreased approximately 0.2-0.6 degrees C after 30 min and continued to decrease further (approximately 0.1-0.2 degrees C) for a period of approximately 10 min after removal of the cooling helmet. Intracranial blood flow decreased significantly (P < 0.05) during the first 10 min of the cooling period. Both right and left ear temperatures in the women were significantly lower than those of the men during the cooling period. These data indicate that head and neck cooling may be used to reduce core temperature to that needed for symptomatic relief of both male and female multiple sclerosis patients. This study quantifies the operating characteristics of one liquid cooling garment as an example of the information needed to compare the efficiency of other garments operated under different test conditions.

Towards a non-invasive interictal application of hypothermia for treating seizures: a feasibility and pilot study

“…Hyperthermia decreases seizure threshold acutely (7), while cortical cooling alters brain electrical behavior leading to increased seizure threshold (8-10, 15, 17, 18) and may acutely stop seizures in animal models and patients (7)(8)(9)(10). Cold saline application stops ongoing after-discharges induced by electrical stimulation, and spontaneous interictal epileptiform discharges (19), and stimulation-evoked seizures (13).…”

“…Shivering was prevented by keeping the torso warm during cooling (13). Cooling efficacy may depend on headgear fit and amount of hair; a 35-year-old man with very short hair whose cooling helmet fit exceptionally well had the lowest IT after 30 min of cooling and the second lowest after 60 min of cooling; head shaving may be beneficial (12).…”

“…Cooling was performed using a head-neck cooling system (CoolSystems, Inc., Lincoln, CA, USA) previously used for anesthetized and/or sedated patients with MS and head injury (12,13). It includes a head/neck liner made of a lightweight, thin, flexible, laminated nylon urethane fabric, and a conditioning unit (temperature control, liquid pump and pressure control, air pump).…”

Head Pre-Cooling Improves Symptoms of Heat-Sensitive Multiple Sclerosis Patients

“…Anecdotal reports from many patients with MS suggest that sensitivity to heat is one of the primary barriers to performing daily activities and participating in exercise and/or rehabilitation, and this sensitivity can lead physicians to advise patients to avoid exercise because metabolic heat production can increase core temperature and thus exacerbate symptoms 3 . In turn, this lower level of physical activity can lead to a further loss of fitness, muscle tone, and most importantly, a decrease in function and quality of life 7,8 . A…”

“…fitting garment around the head, torso, or the whole body, with a network of tubing that fits tightly against the skin and cooling through conduction of cold water 7,8,11,12 . Schwid et al 12 found that cooling the head and torso for 1 or 30 days resulted in a small but significant increase in ambulatory function measured by the 25 foot walk test, and visual function improved as measured by Snellen charts.…”