# HAL Training in Spinal Cord Injured Patients: A Narrative Review of 10 Years Experience
## 3 Results
### Single-Case or Two-Case Reports  
In addition to clinical trials in more or less large collectives, there are some publications that are single case or two case reports on selected issues. For example, [PERSON] et al. [21] published the pain-related data of two subjects from the collective of the [PERSON] et al. [9] study individually. Those chronic patients (both AIS A with ZPP, 10 and 19 years since SCI) had therapy-resistant chronical neuropathic pain. During the course of HAL training, pain symptoms improved in both patients to the extent that medication could be reduced. A brief increase in pain in response to the lower dosage was followed by a renewed reduction in pain during training. Patients changed from a permanent medication to an on-demand medication. The average pain intensity, measured by numerical pain rating scale (NRS-11; 0 = no pain, 10 = worst pain possible), decreased from 4.3 at the first training week to 0.6 after 12 weeks. Furthermore, an improvement on health related QOL in the SF-36 questionnaire was found reflecting the impact of the intervention. According to the authors in a one-year follow up, both patients reported neither recurrence of pain nor need for medication [21]. These results are in contrast to those of [PERSON] et al. [19] who found no changes in pain and QOL in their study. However, the collective in [PERSON] et al. [19] also showed no motor functional improvements while in the study by [PERSON] et al. [21], two patients improved in terms of 10 MWT and LEMS. This could potentially have had an impact on the QOL data. It was also [PERSON] et al. [22] who first reported the use of HAL training in an acutely injured SCI patient in a single case report. The patient had an incomplete motor T10 lesion (AIS C) and began training 77 days after the accident. After 12 weeks HAL training there was recovery of motor functions and walking abilities as shown by increase in WISCI II from 8 to 18 and conversion to AIS D.  
[PERSON] et al. [23] wanted to find out if HAL application was possible in a severely affected chronic complete tetralegic patient and subjected him to 10 HAL trainings in 5 weeks. To perform the treadmill training, two physicians and one therapist were needed. Walking distance and time increased from 25.2 m and 7.6 min to 148.3 m and 15 min and the modified Ashworth scale decreased from 15.3 to 5.75 points after HAL training and lasted for up to 30 min [23]. Therefore, the authors conclude feasibility and efficiency of HAL rehabilitation for tetralegic patients. Another special case is reported by [PERSON] et al. [24] in their presentation of a man whose condition deteriorated due to a spinal dural arteriovenous fistula 19 years after the initial SCI. He underwent surgery and his neurological as well as motor status improved again. Six months post-operatively his improvement had plateaued. This was the point where HAL training started for ten sessions during three months. The patient improved in terms of gait speed and cadence in 10 MWT, International Standards for Neurological and Functional Classification of Spinal Cord Injury (ISNSCI) motor score (14 to 16), WISCI II (7 to 12), manual muscle testing and to some extent in muscle activities measured via EMG. Even though the improvements shown here are not enormous, they do show a further development after the performance increase had initially reached a plateau. The very first application of HAL in the USA is described by [PERSON] et al. [25]. This involved six patients with neurologic motor deficits of various etiologies who underwent 60 HAL sessions in 12 weeks. Among others, one patient was post spinal cord infarction following pulmonary embolism. The aim of this study was to investigate the impact of HAL training on QOL. The spinal cord infarction patient showed improvements in distance on treadmill and in a physical function mobility score. However, she showed a worse QOL after training in a six months follow up.