Diaphragm pacing in spinal cord injury can significantly decrease mechanical ventilation in multicenter prospective evaluation.

BACKGROUND: Cervical spinal cord injury (SCI) can lead to dependence on mechanical ventilation (MV) with significant morbidity and mortality. The diaphragm pacing system (DPS) was developed as an alternative to MV. METHODS: We conducted a prospective single-arm study of DPS in MV-dependent patients with high SCI and intact phrenic nerves. Following device acclimation, pacing effectiveness to provide ventilation was evaluated. The primary endpoint was the number who could use DPS to breathe for 4 continuous hours without MV. Secondary endpoints included the number of patients that could use DPS 24 h/day free of MV and the ability of DPS to maintain clinically acceptable tidal volume (Vt). In addition, we conducted a meta-analysis that included the prospective study along with data from four recently published studies to evaluate DPS hourly use. RESULTS: Fifty-three patients were implanted in the prospective study. Most were male (77.4%) with a median time from injury to treatment of 28.3 (IQR: 12.1, 83.3) months. Four- and 24-h use occurred in 96.2% (95% CI: 87.0%, 99.5%) and 58.5% (95% CI: 44.1%, 74.9%), respectively. Four and 24-h results in the meta-analysis cohort (n = 196) exhibited similar results 92.2% (95% CI: 82.6%, 96.7%) and 52.7% (95% CI: 36.2%, 68.6%) using DPS for 4 and 24 h, respectively. DPS use significantly exceeded the calculated basal tidal volume requirements by a mean of 48.4% (95% CI: 37.0, 59.9%; p < 0.001). CONCLUSIONS: This study demonstrates that in most ventilator-dependent patients, diaphragm pacing can effectively supplement or completely replace the need for MV and support basal metabolic requirements.

Epidemiology of spinal fractures and associated spinal cord injuries in Iceland.

STUDY DESIGN: A retrospective epidemiological study. SETTING: Landspítali University Hospital, Iceland. OBJECTIVES: Assessment of epidemiological data and risk factors for traumatic spinal fractures (SFs) and associated spinal cord injury (SCI). METHODS: A retrospective review of hospital admissions due to traumatic SFs during a 5-year period, with analysis of epidemiological parameters and occurrence of concomitant SCI. Patients with asymptomatic SFs and non-traumatic SCI were excluded. RESULTS: A total of 487 patients were diagnosed with a SF or 310 PMI (per million inhabitants), 42 of them (9%, 27 PMI) with an associated SCI. The mean age was 56 years, males were 57%. Falls were the leading cause of both SFs (49%) and SCIs (43%). Low falls (<1 m) caused SFs more often in elderly women (67%, mean age 77 years) and more than 96% were without SCI. Road traffic accidents (RTA) caused 31% of SFs and 26% of SCIs. Seat belts were not used in 20% of car accidents, but information was missing in 27%. Sports/leisure-related accidents caused SFs in 12% of cases, whereof horseback riding accidents were the most common (36%). CONCLUSIONS: SFs led to SCI in 9% of patients. Several risk factors were common for SFs and SCIs but two major differences were seen: SFs without SCI were most common in older women due to low falls, while the risk of a concomitant SCI increased in young patients, in males, in falls from high levels and when driving without using seat belts. Preventive efforts should therefore be directed towards these risk factors.

[Epidemiology of Spinal Cord Injury in Iceland from 1975 to 2014].

INTRODUCTION: Traumatic spinal cord injury (TSCI) is serious and often has long-term consequences. Since no cure has been found the emphasis has been on preventive measures. The incidence of TSCI varies between countries and the epidemiology has been changing. The aim of this study was to gather epidemiological data on patients with TSCI in Iceland and search for risk factors. MATERIAL AND METHODS: Hospital records of everyone diagnosed with TSCI in 1975-2014 admitted to Landspitali University Hospital were reviewed and information gathered on incidence, age, gender and causes of injury. The American Spinal Injury Association Impairment Scale (AIS) was used to assess the extent of TSCI. RESULTS: A total of 233 patients were diagnosed with TSCI during the study period or 26 per million annually on average. Males were 73% and the mean age was 39 years. Traffic accidents were the most common cause of TSCI. The majority were car rollovers in rural areas. Around 50% did not use a seatbelt. The second most common cause of TSCI were falls. The most common sport/leisure accidents were those related to horseback-riding and winter sports. A third of patients had a complete SCI. At discharge 9% had gained full recovery. CONCLUSIONS: Safe roads and good traffic culture are essential factors in the prevention of serious traffic accidents. Strict safety regulations in the work place and an investigation of causes of falls amongst the elderly could decrease SCIs due to falls. Further preventive measures and protective equipment could possibly be of use in sport- or leisure-related activities. Key words: Traumatic spinal cord injury, incidence, age, gender, causes, extent. Correspondence: Pall E. Ingvarsson, palling@landspitali.is.

Complete worldwide operative experience in laparoscopic diaphragm pacing: results and differences in spinal cord injured patients and amyotrophic lateral sclerosis patients.

BACKGROUND: Diaphragm movement is essential for adequate ventilation, and when the diaphragm is adversely affected patients face lifelong positive-pressure mechanical ventilation or death. This report summarizes the complete worldwide multicenter experience with diaphragm pacing stimulation (DPS) to maintain and provide diaphragm function in ventilator-dependent spinal cord injury (SCI) patients and respiratory-compromised patients with amyotrophic lateral sclerosis (ALS). It will highlight the surgical experiences and the differences in diaphragm function in these two groups of patients. METHODS: In prospective Food and Drug Administration (FDA) trials, patients underwent laparoscopic diaphragm motor point mapping with intramuscular electrode implantation. Stimulation of the electrodes ensued to condition and strengthen the diaphragm. RESULTS: From March of 2000 to September of 2007, a total of 88 patients (50 SCI and 38 ALS) were implanted with DPS at five sites. Patient age ranged from 18 to 74 years. Time from SCI to implantation ranged from 3 months to 27 years. In 87 patients the diaphragm motor point was mapped with successful implantation of electrodes with the only failure the second SCI patient who had a false-positive phrenic nerve study. Patients with ALS had much weaker diaphragms identified surgically, requiring trains of stimulation during mapping to identify the motor point at times. There was no perioperative mortality even in ALS patients with forced vital capacity (FVC) below 50% predicted. There was no cardiac involvement from diaphragm pacing even when analyzed in ten patients who had pre-existing cardiac pacemakers. No infections occurred even with simultaneous gastrostomy tube placements for ALS patients. In the SCI patients 96% were able to use DPS to provide ventilation replacing their mechanical ventilators and in the ALS studies patients have been able to delay the need for mechanical ventilation up to 24 months. CONCLUSION: This multicenter experience has shown that laparoscopic diaphragm motor point mapping, electrode implantation, and pacing can be safely performed both in SCI and in ALS. In SCI patients it allows freedom from ventilator and in ALS patients it delays the need for ventilators, increasing survival.

Manual transport in Parkinson's disease.

We analyze hand dexterity in Parkinson's disease patients (PD) and control subjects using a natural manual transport task (moving an object from one place to another). Eight PD patients and 10 control subjects carried out the task repeatedly at maximum speed both in off and on medicated status. The movement parameters and the grip and load forces were recorded. Using the force and velocity signals, 10 subsequent phases of the transport movement were defined and their durations were measured. The difference between the control group and the test group in off and on was established statistically using non-parametric methods. There was slowed reaching and a striking disturbance of establishing the precision grip in PD. The transport capabilities were impaired differentially. Although acceleration and reaching sufficient height of the lift were disturbed in PD subjects, transport of the object toward the target position was almost normal. A partial disturbance was observed when cancelling the grip. Dopaminergic medication improved only specific hand skills, especially establishment of the precision grip and one of the four transport phases. A long movement path was more sensitive for movement disturbance in Parkinson's disease than a short one.

Grip and load force coordination during a manual transport movement: findings in healthy participants.

During transport of an object using the precision grip with thumb and index finger, a modulation of the grip force is needed in response to the forces evoked by the movement. We measured the grip force (GF) and the load force (LF) in 10 healthy participants moving a 640-g object forward and upward. The task was repeated with various speeds. There were considerable changes with speed of the LF trajectory but not of the GF trajectory. A loss of synergy between GF and LF appeared in fast lifts. This is in contrast to the close coupling between load force and grip force repeatedly demonstrated during simple lifts. We suggest that (a) speed should be considered as an input parameter for movement planning, and (b) regulation of GF and of LF are independent under certain conditions. We discuss whether the grip-load force synergy should be considered a special case rather than a more general principle