Prognostic utility of SEPs in comatose children

Somatosensory evoked potentials (SEPs) were recorded in 73 comatose children upon admission to the intensive care unit and were studied in respect to initial neurologic status and final outcome. SEP results were graded normal, increased interpeak latencies, and unilaterally or bilaterally absent cortical responses. Of the 50 patients with Glasgow Coma Scale scores less than 7 upon admission, only 3 had SEPs within the normal range, while 37 had unilaterally or bilaterally absent SEPs. None of the 27 who died had normal SEPs; 1 had increased interpeak latencies, 26 had more abnormal SEPs. The 14 with normal outcomes had normal (9 patients) or delayed (4 patients) SEPs; the latter group returned to normal within a few days. Repeat SEP studies were performed in 33 patients. SEPs were relatively stable during the intensive care observation, with the exception of 6 patients with Reye syndrome. Subsequent studies are recommended in all patients, but are essential in those with Reye syndrome in order to be useful prognostically. The utility of SEPs did not vary as a function of coma etiology. These data support the usefulness of SEPs in early prediction of neurologic outcome in comatose children.     

Predictors of poor outcome in patients with a spontaneous cerebellar hematoma

BACKGROUND AND PURPOSE: The authors studied the clinical and neuroimaging features of cerebellar hematomas to predict poor outcome using comprehensive statistical models. METHODS: We retrospectively reviewed clinical and neuroimaging features in 94 patients with spontaneous cerebellar hematomas to identify predictive features for a poor neurologic outcome, defined as death or dismissal to long-term care facility. Data were analyzed using chi square and Fisher's exact test with calculation of odd's ratios together with 95% confidence intervals. RESULTS: Clinical and neuroradiologic predictors for a poor outcome at p < 0.05 were admission systolic blood pressure > 200 mm Hg, hematoma size > 3 cm, visible brain stem distortion, and acute hydrocephalus. Presenting findings predicting subsequent death at p < 0.05 were abnormal corneal and oculocephalic responses, Glasgow coma sum score less than 8, motor response less than localization to pain, acute hydrocephalus and intraventricular hemorrhage. CONCLUSION: A tree-based analysis model using binary recursive partitioning showed that cornea reflex, hydrocephalus, doll's eyes, age, and size were the most important discriminating factors. Absent corneal reflexes on admission highly predicts poor outcome (86 percent, confidence limits 67-96 percent). When a cornea reflex is present, acute hydrocephalus predicts poor outcome but only when doll's eyes are additionally absent.     

Evoked potentials in comatose children: auditory brainstem responses

Auditory brainstem responses (ABRs) were studied retrospectively in 80 children (ages 4 days to 19 years) with coma of various etiologies to determine their value as a predictor of outcome. The ABRs performed shortly after admission were analyzed with respect to initial neurologic status and final outcome. Of the 49 patients with initial Glasgow Coma Scale scores of less than 7, only 21 had severely abnormal ABRs. Eighteen had normal ABRs. Of these 18 patients, 10 died, and 8 were neurologically abnormal. Prolonged interpeak latencies were seen in 16 patients who experienced a range of clinical severity. Of the total of 17 children with absent ABRs or only the presence of waves I/III, three children survived, two with minimal neurologic abnormalities and one in a vegetative state. The efficacy of ABRs in comatose children as an early prognostic indicator was not confirmed by this study.     

The role of evoked potentials in anoxic-ischemic coma and severe brain trauma.

The early recognition of comatose patients with a hopeless prognosis-regardless of how aggressively they are managed-is of utmost importance. Median somatosensory evoked potentials supplement and enhance neurologic examination findings in anoxic-ischemic coma and severe brain trauma, and are useful as an early guide to outcome. The key finding is that bilateral absence of cortical evoked potentials, generated by thalamocortical tracts, reliably predicts unfavorable outcome in comatose patients after cardiac arrest, and correlates strongly with death or persistent vegetative state in severe brain trauma. The author studied 50 comatose patients with preserved brainstem function after cardiac arrest. All 23 patients with bilateral absence of cortical evoked potentials died without awakening. Neuropathologic study in seven patients disclosed widespread ischemic changes or frank cortical laminar necrosis. The remaining 27 patients with normal or delayed central conduction times had an uncertain prognosis because some died without awakening or entered a persistent vegetative state. The majority of patients with normal central conduction times had a good outcome, whereas a delay in central conduction times increased the likelihood of neurologic deficit or death. This report includes a systematic review of the literature concerning adults in anoxic-ischemic coma and severe brain trauma, in which somatosensory evoked potentials were used as an early guide to predict clinical outcome. Greater use of somatosensory evoked potentials in anoxic-ischemic coma and severe brain trauma would identify those patients unlikely to recover and would avoid costly medical care that is to no avail.     

Somatosensory evoked potentials in patients with hypoxic coma--correlation with neurologic prognosis

Somatosensory evoked potentials to median nerve stimulations were recorded in 21 patients with hypoxic coma within 24 hours from the onset. According to the neurologic prognosis, the patients were classified into 4 groups, such as I, complete recovery (5 patients), II, partial recovery (3 patients), III, vegetable state (8 patients), IV, brain death (5 patients). Measurements performed include central conduction time (N13-N20 interpeak latency) and amplitude ratio between N20 and P25. As N20 and P25 disappeared in 3 of 8 vegetable patients and all of brain death patients, disappearance of these waves indicates poor neurologic prognosis. Central conduction time showed no significant difference. Amplitude ratio between N20 and P25 (P25/N20) revealed significant decrease in vegetative patients for normal control subjects, complete recovery and partial recovery patients (p less than 0.05). Measurement of this ratio in early phase is useful to predict neurologic outcome in patients with hypoxic coma.     

Central somatosensory conduction time and acoustic brainstem transmission time in post-traumatic coma

Short-latency evoked potentials (SEPs) of the scalp and neck after median nerve stimulation and acoustic brainstem evoked potentials (BAEPs) were recorded in 85 patients in post-traumatic coma with clinical signs of brainstem impairment between days 2 and 6 after trauma. The central somatosensory conduction time (CCT), the amplitude ratio (AR) N20:N13, the interpeak latencies (IPL) I-III, III-V, I-V, and the ARs between waves I and V (I:V) and between wave I and the wave IV/V complex (I:IV/V) were calculated and related to the outcome of the patients. In cases of coma due to supratentorial lesions, CCT and ARs of SEPs were close to normal in patients with good outcome: CCT increased and ARs decreased with worsening of outcome. In cases of primary brainstem injury, a significant prolongation of CCT was also seen in patients with good recovery, whereas normal CCTs could be found in patients with severe disability and death outcome. In this case, unilateral absent scalp SEPs were frequently found. The IPLs I-III, III-V, I-V, and the ARs of BAEPs increased with worsening of outcome. Significant differences of IPL I-V and III-V (brainstem transmission time) were seen between patients with good recovery or moderate disability outcome and the patients with severe disability or death outcome. There was no difference in BAEPs between patients with primary brainstem lesion and patients with secondary brainstem lesion. Patients with bilateral absent SEPs and bilateral absent BAEPs not related to traumatic or preexisting hearing disorders died or survived severely disabled. Unilateral absence of scalp SEPs and unilateral absence of BAEPs were frequently found in patients who died or who had severe disability. Asymmetries in scalp SEPs appeared to be distributed equally to all outcome categories, but asymmetries in BAEPs increased with worsening of outcome too. In most of the patients who died or survived disabled, both SEPs and BAEPs were abnormal.     

Outcome prediction in comatose patients: significance of reflex eye movement analysis.

An analysis of oculocephalic response and vestibuloocular reflex (VOR) in 81 patients with coma from various causes showed the importance of reflex eye movements for outcome prediction. Compared with oculocephalic response testing, VOR analysis provided more evidence and allowed more precise study of ocular motility in comatose patients. In 25 patients (31%) without conclusive or with absent oculocephalic response, a preserved VOR could be seen. The results indicated that in all cases with preserved VOR response (independent of the cause of coma) the assumption of a good outcome is justified and was correct in a maximum of 67%. The unpredictability in the other cases was largely due to non-neurological factors. Ninety two per cent of the patients with abolished reflex eye movements died. The combination of absent VOR and abolished pupillary light reaction allows prediction of negative outcome in 100% and shows the paramount importance of these two brainstem reflexes.     

Methanol poisoning: factors associated with neurologic complications

Hospital records of thirty patients with methanol poisoning were studied. Neurologic manifestations at presentation including coma, seizures and decreased visual acuity were seen in nineteen patients. The mean blood pH at presentation was significantly lower in the patients with these neurologic signs and symptoms than in the eleven patients without them (p less than 0.05). Methanol levels at presentation tended to be higher in patients with neurologic manifestations at presentation and these patients tended to present later after methanol ingestion than those patients without neurologic manifestations. Fifteen patients with methanol poisoning developed serious neurologic sequelae or died. The mean blood pH was significantly lower in this patient group than in those who survived without neurologic sequelae (p less than 0.05). Methanol levels at presentation were not different in the patients who developed neurologic sequelae or died as compared to those who did not. The time from ingestion of methanol to presentation at the hospital was however significantly longer in those patients who developed neurologic sequelae or died (p less than 0.05). Initiation of treatment within eight hours of ingestion of methanol was associated with a better clinical outcome.     

Management of the patient with diminished responsiveness

This article provides a comprehensive overview of the management of patients with coma. The article begins with a discussion of the emergency management of patients presenting with an acute alteration in the level of consciousness. It then reviews concepts on supportive care that are necessary to reduce secondary neurologic injury. A third section addresses management according to the underlying cause of coma, with emphasis on diagnoses that are frequently encountered. Issues related to the long-term management of patients in coma and outcome prediction are briefly discussed.     

Tumor-related epilepsy in children

A 10-year retrospective review of 15 children with cerebral tumors and seizures was conducted to study the factors responsible for delay in the diagnosis of tumors and to assess outcome following surgery. Mean duration of seizures prior to surgery was 37 months. Ninety-three percent had no focal neurologic deficits. Head computed tomography was abnormal in 64%, whereas magnetic resonance imaging was abnormal in all patients. Electroencephalography showed focal abnormalities ipsilateral to the tumor in 73%. There was no surgical mortality. Eighty percent were seizure free or had rare seizures following surgery. Factors contributing to a delayed diagnosis of the brain tumor included a nonfocal neurologic examination and delay in obtaining an appropriate neuroimaging study. We believe that head magnetic resonance imaging should be the investigation of choice in partial epilepsies.     

Heparin treatment in cerebral sinus and venous thrombosis: patients at risk of fatal outcome

We performed a retrospective analysis of 79 patients with cerebral sinus venous thrombosis, who were treated with a fixed regimen of dose-adjusted intravenous heparin, to determine predictors of a fatal course. The parameters investigated were the state of consciousness and the presence of intracranial haemorrhage (ICH) at the start of heparin treatment, involvement of the internal venous system, mean delay from initial symptom to stupor or coma and from initial symptom to hospital admission, focal neurological deficits, mean intracranial circulation time (ICT) on conventional angiography, and age and sex distribution. Mortality rate was 10% in this series (8/79). There was a strong link between the outcome and the level of vigilance: 53% of the patients with stupor or coma at the start of the heparin therapy died (8/15), whereas all of the 64 patients with no more than mildly impaired vigilance survived (p < 0.00001). Furthermore, mean age and mean ICT were significantly higher in the group of patients who died. There was a statistical trend (p = 0.056) for ICH to be more frequent in cases with fatal outcome, but there was reason to assume that ICH represented an epiphenomenon of a severe course rather than an independent predictor. Other investigated parameters were not linked with a fatal outcome.     

Early prognosis in coma after cardiac arrest: a prospective clinical, electrophysiological, and biochemical study of 60 patients.

BACKGROUND: The univariate study of clinical, electrophysiological, or biochemical variables has been shown to predict the outcome in postanoxic coma in about 50% of patients for each type of variable. Previous studies did not, however, consider the prognostic accuracy of a multivariate approach. METHODS: Sixty patients in coma for more than six hours after cardiac arrest were prospectively examined by means of repeated clinical examinations (including Glasgow coma score (GCS)), EEG, and medianus nerve somatosensory evoked potentials (SEPs). In 16 patients, the early concentrations of serum neuron specific enolase and ionised calcium were also measured. RESULTS: Within the first year after cardiac arrest, 20% of patients made a good neurological recovery; 80% remained in a vegetative state or died. Clinical examination correctly predicted outcome in 58% of patients, SEP in 59%, and EEG in 41%. The combination of clinical examination, SEP, and EEG raised the percentage of correct predictions to 82%, without false pessimistic predictions. Concentrations of serum neuron specific enolase and ionised calcium were of no additional prognostic help. Multivariate regression analysis identified the association of GCS < 8 at 48 hours with abnormal or absent early cortical SEPs as highly predictive of a bad outcome (risk = 97%, 95% confidence interval = 86-99%). CONCLUSION: The combination of GCS at 48 hours, SEP, and if these are non-conclusive, EEG, permits a more reliable prediction of outcome in postanoxic coma than clinical examination alone.     

Positive Prognostication from Median-Nerve Somatosensory Evoked Cortical Potentials

Background

The bilateral absence of the cortical N20 median-nerve somatosensory evoked potential (SSEP) is a strong predictor of poor outcome from coma. However, when N20s are present, accurate prognostication is challenging. Here, we investigated the potential for later SSEP components to help disambiguate outcome in these cases.

Methods

In a retrospective review of data from two intensive care units, the amplitudes and latencies of the N20, P25, and N35 components of 28 patients in coma were quantified and related to outcome at discharge from primary care (average 1-month post-injury). Only patients who had survived primary care were included in order to avoid self-fulfilling prophecies, and to focus outcome prediction on those patients with relatively present SSEPs.

Results

The amplitudes of the N20 and N35 components (averaged across hemispheres) significantly predicted the range of outcomes beyond death. Abnormal amplitudes of the N20 and N35—as derived from a healthy control group—were significantly associated with poor outcome. The relative latencies of the cortical components were not related to outcome.

Conclusions

While it is well documented that absent SSEPs are highly predictive of poor outcome, the current data indicate that the relative preservation (absolute amplitude) of “present” N20 and N35 SSEP components can also provide predictive value and thereby inform clinicians and families with decision-making in coma. Further prospective study will elucidate the relative contributions of etiology to the predictive power of these SSEP measures.     

Electrophysiological prognostication and brain injury from cardiac arrest

Anoxic coma after cardiorespiratory arrest warrants precocious investigation to establish probable outcome. Electroencephalogram (EEG) may uncover subclinical seizures; EEG grades have provided accurate prognosis of poor and favorable outcomes, but are weakest in those patients in between. Somatosensory evoked potentials now have proven benefit in accurately establishing a poor outcome (death or persistent vegetative state) when cortical responses (N20) are absent. These studies are particularly helpful when clinical examination of coma, early on, might yield uncertain prognosis (i.e., when brain stem reflexes are present). Combining clinical examination with electrophysiology has increasingly yielded multimodality approaches to early prognostication of coma after cardiorespiratory arrest, with more recent studies using event-related and middle-latency potentials showing promise for distinguishing good outcome (to consciousness), from awake but vegetative states. Further studies are warranted for this multimodality approach which, hopefully, may yield more widespread practical use of these testing modalities.     

Therapeutic Hypothermia After Resuscitation From a Non-Shockable Rhythm Improves Outcomes in a Regionalized System of Cardiac Arrest Care

Objective

Therapeutic hypothermia (TH) improves neurologic outcome in patients resuscitated from ventricular fibrillation. The purpose of this study was to evaluate TH effects on neurologic outcome in patients resuscitated from a non-shockable out-of-hospital cardiac arrest rhythm.

Design and Setting

This is a retrospective cohort study of data reported to a registry in an emergency medical system in a large metropolitan region. Patients achieving field return of spontaneous circulation are transported to designated hospitals with TH protocols.

Patients

Patients with an initial non-shockable rhythm were identified. Patients were excluded if awake in the Emergency Department or if TH was withheld due to preexisting coma or death prior to initiation. The decision to initiate TH was determined by the treating physician.

Measurements

The primary outcome was survival with good neurologic outcome defined by a cerebral performance category of 1 or 2.

Main Results

Of the 2772 patients treated for cardiac arrest during the study period, there were 1713 patients resuscitated from cardiac arrest with an initial non-shockable rhythm and 1432 patients met inclusion criteria. The median age was 69 years [IQR 59–82]; 802 (56 %) male. TH was induced in 596 (42 %) patients. Survival with good neurologic outcome was 14 % in the group receiving TH, compared with 5 % in those not treated with TH (risk difference = 8 %, 95 % CI 5–12 %). The adjusted OR for a CPC 1 or 2 with TH was 2.9 (95 % CI 1.9–4.4).

Conclusion

Analyzing the data collected from the registry of the standard practice in a large metropolitan region, TH is associated with improved neurologic outcome in patients resuscitated from initial non-shockable rhythms in a regionalized system for post-resuscitation care.

     

Prognosis in prolonged coma patients with diffuse axonal injury assessed by somatosensory evoked potential

A total of 43 prolonged coma patients with diffuse axonal injury received the somatosensory evoked potential examination one month after injury in the First Affiliated Hospital, School of Medicine, Zhejiang University in China. Somatosensory evoked potentials were graded as normal, abnormal or absent (grades Ⅰ-Ⅲ) according to N20 amplitude and central conduction time. The outcome in patients with grade Ⅲ somatosensory evoked potential was in each case unfavorable. The prognostic accuracy of grade Ⅲ somatosensory evoked potential for unfavorable and non-awakening outcome was 100% and 80%, respectively. The prognostic accuracy of grade Ⅰ somatosensory evoked potential for favorable and wakening outcome was 86% and 100%, respectively. These results suggest that somatosensory evoked potential grade is closely correlated with coma severity and degree of recovery. Somatosensory evoked potential is a valuable diagnostic tool to assess prognosis in prolonged coma patients with diffuse axonal injury.     

Can we predict poor outcome at presentation in patients with lobar hemorrhage?

OBJECTIVE: Supratentorial lobar hemorrhage can be devastating. Outcome prediction at presentation is important in triage and management decisions as well as appropriate resource utilization. We performed a decision tree analysis combining clinical and CT scan features to predict poor and hopeless outcome at initial presentation in patients with lobar hemorrhage. METHODS: We analyzed 81 patients with spontaneous lobar hemorrhage presenting within 48 hours of initial neurologic symptoms. In the first analysis, poor outcome was defined as Glasgow outcome score (GOS) of 1 (death), 2 (vegetative state) or 3 (dependence) at discharge. A second analysis was based on worst possible outcome (GOS 1-2). Binary recursive partitioning was fitted in a model, and odds ratios with 95% confidence intervals (CI) were calculated. RESULTS: Lobes involved were temporal (36%), parietal (33%), frontal (25%) and occipital (6%). Seventy-three percent of patients presented less than 17 h after initial ictus. The probability of poor outcome was 97% (CI 85-100%) in patients with hemorrhage greater than 40 cm(3). In the subset of patients with a volume less than 40 cm(3), time interval from ictus to presentation (< 17 h) together with a Glasgow coma score (GCS) less than or equal to 13 predicted poor outcome. Eighty-five percent (CI 42-99%) of those presenting early with GCS less than or equal to 13 had a poor outcome. In the second analysis, all patients with GCS less than or equal to 12 and septum pellucidum shift > 6 mm had GOS of 1 or 2 (CI 72-100%). CONCLUSION: Poor outcome in patients with lobar hemorrhage is associated with a hemorrhage size of more than 40 cm(3), GCS less than or equal to 13, but also dependent on time interval between ictus and presentation. This is consistent with prior studies demonstrating deterioration from enlargement may occur when patients present early on. Stupor and septum pellucidum shift greater than 6 mm on CT scan at presentation predict a hopeless outcome in conservatively treated patients. Ninety-one percent of patients were treated medically, thus these outcomes are largely a reflection of the natural history of spontaneous lobar hemorrhage. These signs may influence triage and management decisions.     

Predicting outcome from coma: man-in-the-barrel syndrome as potential pitfall

The Glasgow coma scale motor score is often used in predicting outcome after hypoxic-ischemic coma. Judicious care should be exerted when using this variable in predicting outcome in patients with coma following hypotension since borderzone infarction can obscure the clinical picture. We describe a patient who underwent skull base surgery for a schwannoma of the left facial nerve. The operation, which lasted for 10 h, was conducted under controlled hypotension. After the intervention the patient remained comatose with absent arm movements upon painful stimuli. An absent motor score usually carries a poor prognosis. However, magnetic resonance inversion recovery imaging of the brain showed bilateral hyperintense lesions in the arm-hand area indicative of borderzone ischemic damage. The patient received optimal supportive care and after 17 days he regained consciousness with 'man-in-the-barrel syndrome', which also further improved over time.     

A comparative study of lesionectomy versus corticectomy in patients with temporal lobe lesional epilepsy

We performed a retrospective study comparing surgical outcome of anterior temporal lobectomy (n = 20) and stereotactic lesionectomy (n = 14) in 34 consecutive patients with intractable partial epilepsy evaluated at this institution between June 1986 and June 1992. All patients had medically refractory partial seizures and a neuroimaging-identified temporal lobe foreign-tissue lesion. Patients underwent a pre- and postoperative comprehensive evaluation. In all patients, postoperative neuroimaging studies indicated complete lesion resection. Seventy-one percent of lesionectomy patients and 90% of lobectomy patients, respectively, experienced a worthwhile reduction in seizure tendency. Forty-three percent of lesionectomy patients and 85% of lobectomy patients, respectively, were seizure-free postoperatively. Mean duration of follow-up was 51 months (range, 21–83 months). Morbidity occurred in three patients who underwent corticectomy: complete homonymous hemianopsia (1) and dysphasia (2). No significant morbidity was associated with lesionectomy. Results of this study have altered the surgical strategy at this institution for patients with temporal lobe lesional epilepsy and have proved useful in counseling patients regarding neurologic outcome.     

Amplitude-Integrated Electroencephalography Predicts Outcome in Patients with Coma After Acute Brain Injury

Prognostication of coma patients after brain injury is important, yet challenging. In this study, we evaluated the predictive value of amplitude-integrated electroencephalography (aEEG) for neurological outcomes in coma patients. From January 2013 to January 2016, 128 coma patients after acute brain injury were prospectively enrolled and monitored with aEEG. The 6-month neurological outcome was evaluated using the Cerebral Performance Category Scale. aEEG monitoring commenced at a median of 7.5 days after coma onset. Continuous normal voltage predicted a good 6-month neurological outcome with a sensitivity of 93.6% and specificity of 85.2%. In contrast, continuous extremely low voltage, burst-suppression, or a flat tracing was correlated with poor 6-month neurological outcome with a sensitivity of 76.5% and specificity of 100%. In conclusion, aEEG is a promising predictor of 6-month neurological outcome for coma patients after acute brain injury.