Spinal Decerebrate-Like Posturing After Brain Death: A Case Report and Review of the Literature.

INTRODUCTION: Criteria for establishing brain death (BD) require absence of all brainstem-mediated reflexes including motor (ie, decerebrate or decorticate) posturing. A number of spinal cord automatisms may emerge after BD, but occurrence of decerebrate-like spinal reflexes may be particularly problematic; confusion of such stereotypic extension-pronation movements with brain stem reflexes may confound or delay definitive diagnosis of BD. We present a case in which we verified the noncerebral (ie, likely spinal) origin of such decerebrate-like reflexes. METHODS: Case report and systematic review of literature. RESULTS: A 63-year-old woman presented with large pontine hemorrhage and complete loss of cerebral function, including no motor response to pain. Apnea testing confirmed death by neurologic criteria. Thirty-six hours after BD declaration, during assessment for organ donation, she began to exhibit spontaneous and stimulus-induced stereotypic extension-pronation of the upper extremities. The similarity of these movements to decerebrate posturing prompted concern for retained brain stem function, but repeat neurological examination of cranial nerves and apnea testing did not reveal any cerebral responses. Electrocerebral silence on electroencephalogram and absent perfusion on nuclear medicine brain imaging further confirmed BD. Review of PubMed yielded 5 additional case reports and 4 cohorts describing cases of decerebrate-like extension-pronation movements presenting in a delayed fashion after BD. CONCLUSION: Extension-pronation movements that mimic decerebrate posturing may be seen in a delayed fashion after BD. Verification of lack of any brain activity (by both examination and multiple ancillary tests) in this case and others prompts us to attribute these movements as spinal cord reflexes and propose they be recognized within the rubric of accepted post-BD automatisms that should not delay diagnosis or necessitate confirmatory testing.

MR findings of decerebrate rigidity with preservation of consciousness.

We describe a case of decerebrate rigidity, with preservation of consciousness, caused by a discrete pontine tegmentum lesion identified on MR imaging. Lesions within a certain brain stem region are responsible for decerebrate rigidity in animal studies, but there has been a lack of MR imaging evidence in humans. This report also implies that a discrete lesion was responsible for the decerebrate rigidity, while consciousness was preserved.

Abnormal postural reflexes in a patient with pontine ischaemia.

The control of body posture is a complex activity that needs a very close relationship between different structures, such as the vestibular system, and the muscle and joint receptors of the neck. Damage of even one of these structures can lead to abnormal postural reflexes. We describe a case of a woman with a left pontine ischaemia who developed a 'dystonic' extensor posture of the left limbs while turned on the right side. This clinical picture differs from previous reports on the subject, and may relate to ischaemic damage of a pontine structure involved in posture control, or of adjacent neural connections to be yet identified. To the best of our knowledge, this is the first case reported in the literature. Clinical examples of an altered interplay between vestibular and neck receptors are rare.

Brainstem auditory evoked potentials in syndromes of decerebration, the bulbar syndrome and in central death.

The results are reported of serial brainstem auditory evoked potentials recordings in 51 patients with decerebration and bulbar syndrome. In contrast to the stability of latencies of single components of the potential in healthy subjects, patients with decerebration syndromes show considerable instability and an increase in the latency of all the components of the potential. In 34 decerebrate patients the P-I latency and the interpeak latencies for the medullo-pontine and ponto-mesencephalic segments as well as the central conduction time were significantly increased. There was marked reduction of the amplitude of P-V and P-III and deformation of the single components of the potential with widening and smoothing. The amplitude ratios A-V to A-I and A-III to A-I were significantly decreased. The findings are interpreted as due to mesencephalic and pontine functional disturbance during decerebration. The brainstem auditory evoked potential can be used to estimate the time of brain death. Possible causes of misinterpretation are discussed.

Decerebrate rigidity in humans.

Decerebrate rigidity (DR) in humans results from a midbrain lesion and is manifested by an exaggerated extensor posture of all extremities. It is characterized by shortening and lengthening reactions and can be modified by tonic neck, labyrinthine (Magnus-de Kleijn), and phasic spinal reflexes. These criteria, and not extensor posture alone, reflect the observations of Sherrington and should form the basis of the clinical examination; however, the experimental-anatomical lesion and physiological findings can never be reproduced exactly in humans. "Tonic and cerebellar fits" are not the equivalent of DR, but are forms of muscle spasm that result in an extensor attitude. They are caused by irritation and excitation of the brain stem. The most common cause of DR in humans is trauma. The incidence of DR in head-injured patients may be as high as 40%, resulting in an average mortality rate of 80%; the presence of an extensor posture increases the mortality from 20 to 70%. The surgical removal of an intracranial lesion does not improve the high mortality rate in patients with craniocerebral trauma who are decerebrate. Although the Glasgow coma scale (GCS) does not consider the specific type of central nervous system abnormality caused by trauma, it is an accurate and accepted assessment of outcome after coma lasting longer than 6 hours. DR is a factor in the best motor response of the GCS and should be assigned major importance in the prognosis of comatose head-injured patients.

Syringomyelia presenting as paroxysmal arm posturing resembling seizures.

A 9-year-old female presented with daily episodes of medically refractory paroxysmal bilateral arm posturing, which had long been thought to be epileptic seizures. She also had other types of episodes, including daily staring spells and infrequent generalized tonic-clonic convulsions. Neurologic examination was normal except for delayed cognitive development. The results of previous electroencephalograms (EEG) were normal, and magnetic resonance imaging of the head revealed a Chiari I malformation. Video EEG monitoring revealed no EEG changes during the attacks, and magnetic resonance imaging of the spine revealed a large cervical syrinx associated with the Chiari malformation. The episodes of paroxysmal bilateral dystonic arm posturing resolved after surgical intervention for the syrinx. This report illustrates that cervical cord disease is an unusual although potentially treatable condition to be considered in the differential diagnosis of paroxysmal episodes with dystonic movements of the arms, even in the absence of other physical findings of myelopathy.

Bilateral decerebration in head-injury patients. An analysis of sixty-two cases.

The factors that contributed to recovery were reviewed in 62 head-injured patients with bilateral decerebration. The most important prognostic variables were age, mode of accident, time interval since injury, results of initial neurological evaluations, and the type of intracranial mass lesion. A higher survival rate was recorded in patients less than 20 years of age, those involved in nonvehicular accidents, those admitted within 6 hours of the accident, and where the vestibuloocular reflexes were preserved. Patients with extradural hematomas and those with nonsurgical intracerebral mass lesions also had a relatively better prognosis. In no patient was elective ventilation, steroid, or megadose barbiturate therapy utilized. Twenty patients (32%) of the 62 survived, and 11 patients had a good functional recovery.

[Decerebrate rigidity in craniocerebral injuries (clinico-statistical analysis]. / Detserebratsionnaia rigidnost' pri cherepno-mozgovoi travme (kliniko-statisticheskii analiz).

Decerebrate rigidity (DR) is encountered in 12% of cases with craniocerebral trauma. Statistically significant prevalence of DR in brain compression is shown. Examination of 131 patients with traumatic DR revealed the location of the lesion and the causes of brain compression which led to DR most frequently. The authors distinguish a group of clinico-laboratory signs which have diagnostic and prognostic importance in these patients.

Reversible hepatic decerebration: a case report and review of the literature.

Hepatic encephalopathy is a syndrome of neuropsychiatric dysfunction caused by portosystemic venous shunting with or without the presence of intrinsic liver disease. Clinical presentations are variable ranging from an abnormal sleep pattern to somnolence and deep coma. Decerebrate and decorticate posturing, have been rarely reported with hepatic encephalopathy. We report a case of a 59-year-old-man with a history of Child-Pugh B liver disease secondary to chronic alcoholism who was admitted because of coma. He had a transjugular intrahepatic portosystemic shunt 3 months prior to his presentation. He was found to have decerebrating posture. He was treated for hepatic encephalopathy with complete recovery and resolution of the neurologic findings. The physician should be aware that decerebration and decortication posture can occur with hepatic encephalopathy and can be reversible.

[Motor rhythms synchronous with respiration in the decerebration syndrome of man]. / Uber atmungssynchrone motorische Rhythmen beim Decerebrationssyndrom des Menschen.

Rhythmical somatomotor discharges in the EMG from arms and legs are recorded together with the respiration in decerebrated patients. The rhythms of 7-18/min are synchronous with respiration. The slow activations of 0.3-0.8/min are related to periods of acceleration with higher amplitudes of respiration. The quick rhythms above 2/min correlate with single respiratory movements. They are interpreted as a phenomenon of disinhibition of lower brain stem structures.

Vegetative state following coma in childhood: evolution and outcome.

The data have been analysed for 17 children who showed features of the vegetative state following an acute illness that resulted in coma. 15 were under three years of age. Diffuse anoxia/ischaemia (N=12) and meningitis (N=4) were the most common causes of the comatose state. Seven children died, and nine of the 10 survivors have remained severely neurodevelopmentally handicapped, with no cognitive function (follow-up two months to five years). One child became ambulant a year after the initial insult and is moderately retarded. The findings suggest that children who develop the vegetative state following an illness resulting in coma have a poor prognosis and that decorticate or decerebrate responses, roving eye-movements and spontaneous blinking may be early indicators of its emergence.

Electroencephalographic correlates of near-drowning encephalopathy in children.

Findings of the serial EEGs of 9 children involved in fresh water near-drowning were correlated with neurological signs and final outcome. Our observations revealed that in young near-drowning victims there is a distinct evolution of the EEG which differs considerably from any stereotyped classification outlined for other types of encephalopathies. In patients with a poor clinical outcome, the early phase of near-drowning encephalopathy was characterized electrically by diffuse delta waves, often with alpha or beta frequencies superimposed (alpha-delta and beta-delta pattern). Additional features included poor sleep-waking differentiation and abnormal reactivity. Repetitive focal or multifocal biphasic or triphasic wave forms occurred exclusively in the group with a fatal outcome. The intermediate phase of the encephalopathy was signaled by an attenuation of all fast frequencies (alpha and beta rhythms), enhancement of delta activity, and disappearance of sleep parameters (if present in the earlier recordings). Finally, a modified burst suppression pattern occurred as a late EEG evolution in an encephalopathy of complex and protracted nature.