Unconsciousness or unresponsiveness in akinetic mutism? Insights from a multimodal longitudinal exploration.

The clinical assessment of patients with disorders of consciousness (DoC) relies on the observation of behavioural responses to standardised sensory stimulation. However, several medical comorbidities may directly impair the production of reproducible and appropriate responses, thus reducing the sensitivity of behaviour-based diagnoses. One such comorbidity is akinetic mutism (AM), a rare neurological syndrome characterised by the inability to initiate volitional motor responses, sometimes associated with clinical presentations that overlap with those of DoC. In this paper, we describe the case of a patient with large bilateral mesial frontal lesions, showing prolonged behavioural unresponsiveness and severe disorganisation of electroencephalographic (EEG) background, compatible with a vegetative state/unresponsive wakefulness syndrome (VS/UWS). By applying an unprecedented multimodal battery of advanced imaging and electrophysiology-based techniques (AIE) encompassing spontaneous EEG, evoked potentials, event-related potentials, transcranial magnetic stimulation combined with EEG and structural and functional MRI, we provide the following: (i) a demonstration of the preservation of consciousness despite unresponsiveness in the context of AM, (ii) a plausible neurophysiological explanation for behavioural unresponsiveness and its subsequent recovery during rehabilitation stay and (iii) novel insights into the relationships between DoC, AM and parkinsonism. The present case offers proof-of-principle evidence supporting the clinical utility of a multimodal hierarchical workflow that combines AIEs to detect covert signs of consciousness in unresponsive patients.

Tacrolimus-Induced Akinetic Mutism or Epidural Catheter Migration: A Case Report.

Differential diagnosis of the underlying cause of new-onset total body paralysis can be challenging and unsatisfying. In akinetic mutism, a rare side effect of tacrolimus, patients become apathetic, mute, and lose voluntary muscle movement. Epidural subarachnoid migration can present with similar symptoms. Delayed emergence/paralysis after anesthesia can include the common culprits of residual operative medications, stroke, as well as tacrolimus-induced akinetic mutism and thoracic epidural migration. We present a case of new-onset total body paralysis, presenting on postoperative day 1 following a double-lung transplant in a patient started on tacrolimus with a thoracic epidural catheter in place.

Encephalopathy With Akinetic Mutism in a Child With COVID-19 Infection: A Case Report.

INTRODUCTION: COVID-19 has been associated with neurological complications, including encephalopathy and akinetic mutism. CASE PRESENTATION: A 7-year-old unvaccinated boy presented with visual hallucinations, urinary incontinence, and akinetic mutism 13 days after he was exposed to COVID-19. He had minimal respiratory symptoms, including just 1 day of fever and cough. Evaluations showed slowing on electroencephalogram, normal cerebrospinal fluid, normal brain magnetic resonance imaging, and mild sinus bradycardia. He recovered rapidly to baseline after 5 days of intravenous methylprednisolone. DISCUSSION: COVID-19-related encephalopathy including akinetic mutism is usually found in older adult patients with more severe COVID-19 illness. Our case demonstrates that akinetic mutism can present in children with mild COVID-19 illness and that it can respond rapidly and completely to intravenous methylprednisolone. CONCLUSIONS: COVID-19-related encephalopathy may be immune mediated. A heightened awareness of its association with COVID-19 illness should lead to earlier diagnosis and consideration of immunomodulatory therapy.

A Review of Studies on the Role of Diffusion Tensor Magnetic Resonance Imaging Tractography in the Evaluation of the Fronto-Subcortical Circuit in Patients with Akinetic Mutism.

Akinetic mutism (AM) is characterized by the complete absence of spontaneous behavior (akinesia) and speech (mutism) with the preservation of executive functions for movements and speaking. Elucidation of the pathophysiological mechanisms or neural correlates for AM is clinically important because patients can recover from AM after medication and neuromodulation. The fronto-subcortical circuit is a critically important neural structure in the pathophysiology of AM. Using diffusion tensor tractography, a few neural tracts in the fronto-subcortical circuit can be reconstructed. This mini-review article evaluated 6 DTT-based studies on the fronto-subcortical circuit injury in patients with AM. According to these results, the neural tracts among the fronto-subcortical circuit, which are related to AM, were as follows (in decreasing order of importance): 1) the prefronto-caudate tract, 2) the prefronto-thalamic tract, and 3) the cingulum. In particular, the medial prefrontal cortex is an important brain area related to recovery from AM. However, only 6 studies on this topic have been published, and most were case reports. In addition, these studies analyzed only a few neural tracts in the fronto-subcortical circuit. Because AM is a rare disorder, studies involving a large number of subjects might be impossible. Nevertheless, an analysis of various neural tracts in the fronto-subcortical circuit is necessary. For this, reconstruction of the other neural tracts in the fronto-subcortical circuit should be performed first. This review aims to present the findings from recent studies on the role of DTT in evaluation of fronto-subcortical circuit injury in patients with AK.

Akinetic mutism following prefrontal injury by an electrical grinder a case report: A diffusion tensor tractography study.

RATIONALE: A 72-year-old male had suffered from head trauma resulting from injury to his frontal area by an electrical grinder while working at his home. PATIENT CONCERNS: He lost consciousness for approximately 10 minutes and experienced continuous post-traumatic amnesia. DIAGNOSES: He was diagnosed as traumatic intracerebral hemorrhage in both frontal lobes, intraventricular hemorrhage, and subarachnoid hemorrhage, and underwent decompressive craniectomy and hematoma removal. INTERVENTIONS: The patient's Glasgow Coma Scale score was 5. At 2 months after onset, when starting rehabilitation, he showed no spontaneous movement or speech; he remained in a lying position all day with no spontaneous activity. OUTCOMES: On 2-month diffusion tensor tractography, decreased neural connectivity of the caudate nucleus to the medial prefrontal cortex (PFC, Broadmann area [BA]: 10 and 12) and orbitofrontal cortex (BA 11 and 13) was observed in both hemispheres. LESSONS: Akinetic mutism following prefrontal injury.

Mumps encephalitis with akinesia and mutism.

Measles-rubella-mumps vaccination is routine in many countries, but the mumps vaccine remains voluntary and is not covered by insurance in Japan. A 5-year-old Japanese boy who had not received the mumps vaccine was affected by mumps parotitis. Several days later, he presented with various neurological abnormalities, including akinesia, mutism, dysphagia, and uncontrolled respiratory disorder. Mumps encephalitis was diagnosed. Despite steroid pulse and immunoglobulin treatment, the disease progressed. Magnetic resonance imaging showed necrotic changes in bilateral basal ganglia, midbrain, and hypothalamus. At 1 year follow up, he was bedridden and required enteral feeding through a gastric fistula and tracheostomy. Mumps vaccination should be made routine as soon as possible in Japan, because mumps encephalitis carries the risk of severe sequelae.

Ganser-like syndrome after loss of psychic self-activation syndrome: psychogenic or organic?

Very few data are available on the long-term changes in the cognitive abilities of patients with loss of psychic self-activation syndrome (LPSAS). Here, we present a 25-year follow-up study on a case of LPSAS resulting from bilateral pallidal lesions caused by carbon monoxide intoxication. Typical signs of LPSAS were observed, showing no changes in severity, but Ganser syndrome (GS) gradually developed and worsened during the follow-up period. GS is generally assumed to be a psychogenic syndrome, but an organic etiology has been suspected by the authors of several case reports. Here, atypical features of GS plead against the independence of GS and LPSAS. DaTSCAN and brain 18FDG-PET were performed. Since left hippocampal hypometabolism has been previously described in patients with functional amnesia, it is possible that long periods of mental inactivity may have psychological consequences, but the atypical features of GS also suggest that an organic mechanism may be involved.

Acute inferior homonymous quandrantanopia in a 71-year-old woman.

A 71-year-old woman presented with acute inferior homonymous quadrantanopia initially mimicking acute ischemic stroke. As clinical signs and symptoms progressed to akinetic mutism with myoclonus the diagnosis of the Heidenhain variant of Creutzfeldt-Jakob disease was made. Brain MRI 4 days after symptom onset revealed ribbon-like high signal intensity in the medial occipital cortex.

[A case of intraventricular meningioma manifesting akinetic mutism after complicated management of hydrocephalus].

A 26-year-old male with large intraventricular meningioma developed acute hydrocephalus postoperatively, which was difficult to manage. After a repeated course of dilated and slit-like ventricle, he gradually presented a disturbance of consciousness, which was recovered by the use of bromocriptine, suggesting akinetic mutism. At the chronic stage, he suffered from symptoms of hydrocephalus again. Time-slip MRI revealed the stasis of CSF flow around the third ventricle. Neuroendoscopy disclosed that the foramen of Monro was occluded with membrane. After endoscopic third ventriculostomy as well as penetration of the foramen, the symptoms disappeared and hydrocephalus was resolved. This is a rare case of akinetic mutism after complicated management of hydrocephalus associated with intraventricular meningioma.

Akinetic mutism without a structural prefrontal lesion.

Akinetic mutism is characterized by profound apathy and a lack of verbal and motor output for action, despite preserved alertness. The condition usually follows bilateral damage to the medial frontal subcortical circuits. We report a 59-year-old right-handed woman who was admitted to the neurology ward with sudden-onset akinetic mutism. Her medical history included an ischemic stroke 3 years earlier, with residual anomia and mild agraphia but no motor dysfunction. On this admission, a cranial computed tomography scan disclosed an acute left superior cerebellar infarction embracing the vermis, and a prior left inferior parietal infarct. Electroencephalogram showed bilateral frontal delta-wave activity. Four weeks later, we performed a technetium-99m hexamethylpropyleneamine oxime single-photon emission computed tomography (Tc-HMPAO SPECT) scan to study the patient's frontal lobe function. The SPECT scan revealed the causative bifrontal hypoperfusion, more prominent on the right, while the structurally evident cerebellar infarction was predictably masked by subacute hyperperfusion phenomenon. Contralateral frontal diaschisis is an established sequela of cerebellar infarction. Because this patient also had lesions in the left parietal region, her left prefrontal area was critically deprived of its major reciprocally connected cortical counterparts (right prefrontal and left parietal), and also became dysfunctional. Her resulting bilateral frontal dysfunction is a common cause of akinetic mutism.

[Rare consciousness disturbances in toxicological practice: akinetic mutism, somnambulism, locked-in syndrome, and psychogenic coma]. / Rzadkie zaburzenia swiadomosci w praktyce toksykologicznej: mutyzm akinetyczny, somnambulizm, zespól zamkniecia i spiaczka psychogenna.

The toxicity of xenobiotics can result inrare disorders of consciousness, such as akinetic mutism and somnambulism as well as syndromes mimicking consciousness disturbances, such as locked-in syndrome and psychogenic coma. Akinetic mutism is a condition characterized by a lack of spontaneous movements and little or no vocalization. Somnambulism include performing of complex motor activity in an automatic manner during deep sleep, without any awareness of its execution. The locked-in syndrome is a state with quadriplegia coexisting with cranial nerves palsies and mutism, but with fully preserved consciousness. Psychogenic coma is a condition in which the patient has preserved level of consciousness and awareness, but does not communicate with theenvironment and does not exhibit the external manifestations of consciousness. This paper presents the etiology, clinical characteristics, as well as diagnostic and therapeutic issues for the above syndromes.

Akinetic mutism caused by HIV-associated progressive multifocal leukoencephalopathy was successfully treated with mefloquine: a serial multimodal MRI Study.

We report a case of a patient with highly active anti-retroviral therapy-resistant human immunodeficiency virus (HIV)-associated progressive multifocal leukoencephalopathy (PML). The patient showed an improvement in imaging findings and clinical symptoms after mefloquine was introduced as an additional treatment. Serial assessment of white matter lesions was conducted by proton magnetic resonance spectroscopy ((1)H-MRS) and diffusion-weighted imaging (DWI). As the clinical symptoms improved, the N-acetylaspartate/creatine ratio increased, the choline/creatine ratio decreased, and the elevated ADC value decreased. These concomitant changes suggested that (1)H-MRS and DWI were useful for the assessment of the therapeutic effect on PML.

Reversible acute encephalopathy with mutism, induced by calcineurin inhibitors after renal transplantation.

The incidence of neurotoxicity from calcineurin inhibitors varies by the organ transplanted. Akinetic mutism is characterized by the inability to perform voluntary movements and express language, without alterations in mental status. This process has been reported in neurotoxicity due to high serum levels of calcineurin inhibitors, but in rare cases, it presents as a form of tacrolimus toxicity after renal transplantation, despite normal serum levels. We report a clinical case of a renal transplant patient in whom reversible acute encephalopathy and akinetic mutism developed. Brain lesions appeared on magnetic resonance imaging, and the condition resolved after the drug was withdrawn.

The neurology of decreased activity: abulia.

Delirium is sometimes defined as acute onset of either overactivity or underactivity. This article reviews the nature and clinico-anatomical locations of lesions in patients with reduced activity. The term abulia is used to describe global underactivity. Abulia is customarily explained by interruptions in frontal-subcortical circuitry. These interruptions can occur with lesions in the frontal lobes, caudate nuclei, midbrain, and thalamus. The article describes the anatomy of frontal and subcortical circuits and reviews in detail individual cases and series of patients with reduced initiative and activity who have had localized central nervous system lesions.

The assessment of decisional capacity.

The physician must explain the treatment or procedure in detail including risks, benefits, and alternative options; the patient's choice must be voluntary; the patient must demonstrate his or her ability to understand the risks and benefits of their choice; and the patient must be able to manipulate information in a logical way. These criteria must be met in order for the process of informed consent to be valid.

Delayed akinetic catatonic mutism following methadone overdose.

A 49-year-old woman developed a catatonic mute state a few weeks after methadone overdose. Clinical, radiological and histological findings were consistent with toxic spongiform leukoencephalopathy, which adds a potentially deadly side-effect to a generally considered safe substitution for heroin.