Olfactory sniffing signals consciousness in unresponsive patients with brain injuries.

After severe brain injury, it can be difficult to determine the state of consciousness of a patient, to determine whether the patient is unresponsive or perhaps minimally conscious1, and to predict whether they will recover. These diagnoses and prognoses are crucial, as they determine therapeutic strategies such as pain management, and can underlie end-of-life decisions2,3. Nevertheless, there is an error rate of up to 40% in determining the state of consciousness in patients with brain injuries4,5. Olfaction relies on brain structures that are involved in the basic mechanisms of arousal6, and we therefore hypothesized that it may serve as a biomarker for consciousness7. Here we use a non-verbal non-task-dependent measure known as the sniff response8-11 to determine consciousness in patients with brain injuries. By measuring odorant-dependent sniffing, we gain a sensitive measure of olfactory function10-15. We measured the sniff response repeatedly over time in patients with severe brain injuries and found that sniff responses significantly discriminated between unresponsive and minimally conscious states at the group level. Notably, at the single-patient level, if an unresponsive patient had a sniff response, this assured future regaining of consciousness. In addition, olfactory sniff responses were associated with long-term survival rates. These results highlight the importance of olfaction in human brain function, and provide an accessible tool that signals consciousness and recovery in patients with brain injuries.

The role of comprehensive rehabilitation in the care of degenerative cervical myelopathy.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To find out if comprehensive rehabilitation itself can improve daily performance in persons with DCM. SETTING: The spinal department of a rehabilitation hospital. METHODS: Data from 116 DCM inpatients who underwent comprehensive rehabilitation after spinal surgery were retrospectively analyzed. The definitions of the calculated outcome variables made possible analyses that distinguished the effect of rehabilitation from that of spinal surgery. Paired t-tests were used to compare admission with discharge outcomes and functional gains. Spearman's correlations were used to assess relationships between performance gain during rehabilitation and between time from surgery to rehabilitation. RESULTS: The Spinal Cord Injury Ability Realization Measurement Index (SCI-ARMI) increased during rehabilitation from 57 (24) to 78 (19) (p < 0.001). The Spinal Cord Independence Measure 3rd version (SCIM III) gain attributed to neurological improvement (dSCIM-IIIn) was 6.3 (9.2), and that attributed to rehabilitation (dSCIM-IIIr) 16 (18.5) (p < 0.001). dSCIM-IIIr showed a rather weak negative correlation with time from spinal surgery to rehabilitation (r = -0.42, p < 0.001). CONCLUSIONS: The study showed, for the first time, that comprehensive rehabilitation can achieve considerable functional improvement for persons with DCM of any degree, beyond that of spinal surgery. Combined with previously published evidence, this indicates that comprehensive rehabilitation can be considered for persons with DCM of any functional degree, before surgery.

[THE CONTRIBUTION OF INPATIENT REHABILITATION IN ISRAEL TO THE IMPROVEMENT OF DAILY FUNCTIONING AFTER SPINAL CORD LESIONS].

INTRODUCTION: Spinal cord lesions (SCL) are usually followed by neurological and functional improvement. The neurological improvement is natural and improves the functional potential of the patients, while rehabilitation improves the realization of that potential. The functional change depends on the neurological change, and usually does not represent the contribution of rehabilitation alone to the functional improvement. AIMS: To evaluate the net contribution of inpatient rehabilitation in Israel to functioning after SCL, and the ability to predict this contribution, which reflects the success of rehabilitation. METHODS: Demographic and clinical data of SCL patients admitted to rehabilitation between 2011 and 2020 were collected retrospectively. The data were used to calculate Spinal Cord Injury Ability Realization Measurement Index (SCI-ARMI) scores, isolating the effect of neurologic status on functioning, its change during rehabilitation, and factors affecting it. Data were analyzed using t-tests, Pearson correlations, ANOVA, and ANCOVA. RESULTS: A total of 1,433 patients were included in the study. Their age was 54±17 years, 32% were females, and 37.2% had traumatic injuries. American Spinal Injury Association Impairment Scale (AIS) grades were A in 11% of the patients, B in 4.8%, C in 17.3% and D in 65.9%. SCI-ARMI was 52±24 at admission to rehabilitation, and 73.5±19 at discharge (41% improvement, p<0.001). Likewise, the neurological motor status and function significantly improved. SCI-ARMI improvement increased with lower admission SCI-ARMI values (r=-0.654, p<0.001) and younger age (r=-0.122, p<0.001), and correlated with longer stay in rehabilitation (r=0.261, p<0.001). CONCLUSIONS: Inpatient rehabilitation in Israel made a substantial contribution to functional improvement. Lower realization of the functional potential at admission to rehabilitation predicted greater success in the process of SCL rehabilitation.

Responses to stimuli in the 'snoezelen' room in unresponsive wakefulness or in minimally responsive state.

BACKGROUND: Sensory stimulation in Snoezelen room increased responsiveness after brain injury and dementia. OBJECTIVE: To explore the physiological and clinical effects of Snoezelen stimulation in persons with unresponsive wakefulness syndrome or minimally conscious state (UWS or MCS). DESIGN: A comparative prospective observational cohort study. METHODS: Ten patients with UWS and 25 in MCS were exposed to consecutive stimuli involving the 5 senses in a Snoezelen room. Heart rate (HR) and cerebral blood flow velocity (CBFV), and scores of the Loewenstein communication scale (LCS) were obtained before and during or after the stimuli. RESULTS: The stimuli increased HR values and decreased left hemisphere CBFV values in patients with MCS (p < 0.05). Stimulation increased LCS scores (from 28.48 ± 6.55 to 31.13 ± 7.14; p < 0.001) in patients with MCS, but not in the UWS group. LCS gain correlated with HR and right hemisphere CBFV gains in patients with MCS (r = 0.439 and 0.636 respectively, p < 0.05). CONCLUSIONS: Snoezelen stimulation induced immediate improvement in communication and physiological changes in patients with MSC, and had a minor physiological effect in patients with UWS. If additional studies support these findings, it will be possible to suggest that Snoezelen stimulation can affect arousal, and possibly improve functioning.

Consciousness recovery after various periods in vegetative state.

BACKGROUND: Recent studies suggest that late recovery from vegetative state (VS) is more prevalent today than previously thought. This study examined the decline in the rate of recovery from VS with time after admission to rehabilitation, and established a new time frame, in which the odds of recovery from VS remain substantial. METHODS: Data of 206 patients with VS after traumatic and non-traumatic brain injuries (TBI and NTBI), who were treated at the Loewenstein Rehabilitation Hospital (LRH), in Raanana, Israel, between 2003 and 2015, and described in a previous publication, were further analysed. Rate of recovery from VS was monitored at several time points after admission to intensive care and consciousness rehabilitation (ICCR). RESULTS: The odds of consciousness recovery were at least 54% at admission to ICCR, and 48%, 33%, 19%, and 7% at 3, 6, 9, and 12 months after admission, respectively. CONCLUSIONS: The rate of recovery from VS decreases significantly with time, but contrary to previous consensus, 6-12 months after admission to ICCR, the odds of recovery from VS after TBI and NTBI remain substantial.

Vegetative state outcomes improved over the last two decades.

OBJECTIVE: To describe late outcomes in patients with prolonged unawareness, and factors affecting them. DESIGN: A retrospective study of 154 patients with traumatic brain injury (TBI) and 52 with non-traumatic brain injury (NTBI), admitted for intensive care and consciousness rehabilitation (ICCR), in a vegetative state (VS) lasting over 1 month. RESULTS: Survival rate (67% total) was higher than in past studies carried out at the same facility (p < 0.01). Consciousness recovery rate (54% total) was higher in NTBI VS patients (p < 0.01) than in earlier cohorts, and similar in TBI VS patients, despite their older age than that of earlier cohorts. No meaningful differences were found in characteristics or in outcomes between the TBI and NTBI groups. Age, length of stay in ICCR, and hydrocephalus were found to affect survival (p < 0.001). Younger age, absence of hydrocephalus, and anti-Parkinsonian medication contributed to consciousness recovery after VS (p < 0.05). CONCLUSIONS: The present study demonstrated an improvement in survival and recovery of consciousness in VS patients over the last two decades, and similar outcomes for both TBI and NTBI VS. Outcomes suggest that acute medical care and ICCR have contributed to advances in VS care.

The effect of cranioplasty on outcomes and complications of unresponsive wakefulness syndrome and minimally responsive state.

Background Studies that have shown neurological improvement following cranioplasty (CP) after decompressive craniectomy (DC) in patients with unresponsive wakefulness syndrome (UWS) and minimally conscious state (MCS) did not include control groups. The aim of this study was to assess the justification of CP for these patients. Methods Data were collected from medical records of inpatients with UWS and MCS admitted between 2002 and 2018. Results Of the 144 participants (mean age 40 years, 76% males, 75% in UWS), 37% had CP following DC. The Loewenstein Communication Scale (LCS) gain was 12±17 and 16±17 for the control and study patients, respectively. The corresponding consciousness recovery rate (based on Coma Recovery Scale-Revised scores) was 51% and 53%, respectively. One-year survival rates were 0.80 and 0.93, and 5-year survival rates were 0.67 and 0.73, respectively. Mean outcome values were higher for the study group, but the differences between the groups did not reach statistical significance. Conclusions The study did not demonstrate that CP increases brain recovery or survival. Nevertheless, it showed that CP did not decrease them either, and it did not increase complications rate. The findings, therefore, support offering CP to patients with UWS and MCS as CP does not increase risks and can achieve additional goals for these patients.

Assessment of ability realization using the 4th version of the Spinal Cord Independence Measure.

CONTEXT: Change in ability realization reflects the main contribution of rehabilitation to improvement in the performance of daily activities after spinal cord lesions (SCL). OBJECTIVE: To adapt a Spinal Cord Ability Realization Measurement Index (SCI-ARMI) formula to the new Spinal Cord Independence Measure version 4 (SCIM4). METHODS: Using data from 156 individuals for whom American Spinal Injury Association Motor Score (AMS) and SCIM4 scores were collected, we obtained an estimate for the highest possible SCIM4 given the patient's AMS value, using the 95th percentile of SCIM4 values at discharge from rehabilitation (SCIM95) for patients with any given AMS at discharge. We used the statistical software environment R to implement the quantile regression method for linear and quadratic formulas. We also compared the computed model with the SCIM95 model obtained using data from the present study group, positioned in the SCIM95 formula developed for SCIM3. RESULTS: The coefficients of the computed SCIM95 formula based on SCIM4 scores were statistically non-significant, which hypothetically reflects the small sample relative to the goal of estimating SCIM4 95th percentile. Predicting the ability using SCIM4 scores positioned in the SCIM95 formula used for SCIM3, however, yielded SCIM95 values, which are very close to those of the new SCIM95 formula (Mean difference 2.16, 95% CI = 1.45, 4.90). CONCLUSION: The SCI-ARMI formula, which is based on the SCIM95 formula developed for SCIM3, is appropriate for estimating SCI-ARMI at present, when SCIM4 scores are available. When sufficient additional data accumulates, it will be appropriate to introduce a modified SCI-ARMI formula.

The net contribution of rehabilitation to improvement in performance in patients with spinal cord lesions in five countries.

CONTEXT: Change in ability realization reflects the main contribution of rehabilitation to improvement in the performance of daily activities in patients with spinal cord lesions (SCL). OBJECTIVE: To assess the net effect of rehabilitation of patients with SCL and compare it between countries. METHODS: We calculated the Spinal Cord Ability Realization Measurement Index (SCI-ARMI) and its change from admission to rehabilitation to discharge, for inpatients admitted to SCL units in five countries, between 2016 and 2019. We used chi-square tests, analysis of variance (ANOVA), McNemar's test, Pearson's correlations, and analysis of covariance (ANCOVA) to compare countries and patient groups and assess the relationships of various factors with SCI-ARMI gain during rehabilitation. RESULTS: The study included 218 inpatients (67% males, age 52 ± 17). In Brazil, Israel, Italy, Portugal, and Turkiye, respectively, SCI-ARMI gain was 2 (SD = 15), 19 (SD = 17), 31 (SD = 23), 13 (SD = 15), and 16 (SD = 12). Yet, after controlling for admission SCI-ARMI and the time from SCL onset to the examination, the effect of the country on ability realization gain was found non-significant (P = 0.086). CONCLUSION: The study confirmed that rehabilitation makes a net contribution to improvement in performance in patients with SCL, beyond the contribution of neurological recovery. After controlling for affecting factors, this contribution was quite similar in the participating units from different countries.

Venous thromboembolism and anticoagulation in spinal cord lesion rehabilitation inpatients: A 10-year retrospective study.

BACKGROUND: Venous thromboembolism (VTE) is a concern following the onset of spinal cord lesions (SCL). OBJECTIVES: To assess the current efficacy and risks of anticoagulation after SCL and consider changes in thromboprophylaxis. METHODS: This retrospective cohort study included individuals admitted to inpatient rehabilitation within 3 months of SCL onset. Main outcome measures were the incidence of deep vein thrombosis (DVT), pulmonary embolism (PE), bleeding, thrombocytopenia, or death, which occurred within 1 year of the SCL onset. RESULTS: VTE occurred in 37 of the 685 patients included in the study (5.4%, 95% CI 3.7-7.1%, 2.8% PE), and in 16 of 526 patients who received prophylactic anticoagulation at rehabilitation (3%, 95% CI 1.6-4.5%, 1.1% PE, with at least 1 fatality). Of these 526, 1.3% developed clinically significant bleeding and 0.8% thrombocytopenia. Prophylactic anticoagulation, most commonly 40 mg/day, continued until a median period of 6.4 weeks after SCL onset (25% -75% percentiles 5.8-9.7), but in 29.7%, VTE occurred more than 3 months after SCL onset. CONCLUSION: The VTE prophylaxis used for the present cohort contributed to a considerable but limited reduction of VTE incidence. The authors recommend conducting a prospective study to assess the efficacy and safety of an updated preventive anticoagulation regimen.

Using a Sniff Controller to Self-Trigger Abdominal Functional Electrical Stimulation for Assisted Coughing Following Cervical Spinal Cord Lesions.

Individuals with cervical spinal cord lesions (SCLs) typically depend on caregivers to manually assist in coughing by pressing against their abdominal wall. Coughing can also be assisted by functional electric stimulation (FES) applied to abdominal muscles via surface electrodes. Efficacy of FES, however, depends on precise temporal synchronization. The sniff controller is a trigger that enables paralyzed individuals to precisely control external devices through alterations in nasal airflow. We hypothesized that FES self-triggering by sniff controller may allow for effective cough timing. After optimizing parameters in 16 able-bodied subjects, we measured peak expiratory flow (PEF) in 14 subjects with SCL who coughed with or without assistance. Assistance was either manual assistance of a caregiver, caregiver activated FES, button self-activated FES (for SCL participants who could press a button), or sniff-controlled self-activated FES. We found that all assisted methods provided equally effective improvements, increasing PEF on average by 25 ± 27% (F[4,52] = 7.99, p = 0.00004 ). There was no difference in efficacy between methods of assistance ( F[3,39] = 0.41, p = 0.75 ). Notably, sniff-controlled FES was the only method of those tested that can be activated by all paralyzed patients alone. This provides for added independence that is a critical factor in quality of life following SCL.

An international age- and gender-controlled model for the Spinal Cord Injury Ability Realization Measurement Index (SCI-ARMI).

Background. A quadratic formula of the Spinal Cord Injury Ability Realization Measurement Index (SCI-ARMI) has previously been published. This formula was based on a model of Spinal Cord Independence Measure (SCIM95), the 95th percentile of the SCIM III values, which correspond with the American Spinal Injury Association Motor Scores (AMS) of SCI patients. Objective. To further develop the original formula. Setting. Spinal cord injury centers from 6 countries and the Statistical Laboratory, Tel-Aviv University, Israel. Methods. SCIM95 of 661 SCI patients was modeled, using a quantile regression with or without adjustment for age and gender, to calculate SCI-ARMI values. SCI-ARMI gain during rehabilitation and its correlations were examined. Results. A new quadratic SCIM95 model was created. This resembled the previously published model, which yielded similar SCIM95 values in all the countries, after adjustment for age and gender. Without this adjustment, however, only 86% of the non-Israeli SCIM III observations were lower than those SCIM95 values (P < .0001). Adding the variables age and gender to the new model affected the SCIM95 value significantly (P < .04). Adding country information did not add a significant effect (P > .1). SCI-ARMI gain was positive (38.8 ± 22 points, P < .0001) and correlated weakly with admission age and AMS. Conclusions. The original quadratic SCI-ARMI formula is valid for an international population after adjustment for age and gender. The new formula considers more factors that affect functional ability following SCI.

Post irradiation myelopathy: from the physiatrists' point of view.

We describe two patients who developed a severe spinal cord damage long time after cessation of irradiation therapy. The various and unique rehabilitation medicine aspects are discussed and the literature is surveyed.