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Handbook of Clinical Neurology 2023The motor phenomena accompanying frontal lobe disease are diverse, reflecting the various roles the frontal lobes play in the organization of motor control. The... (Review)
Review
The motor phenomena accompanying frontal lobe disease are diverse, reflecting the various roles the frontal lobes play in the organization of motor control. The principal frontal motor areas, the primary motor cortex, the premotor cortex, and the supplementary motor area, have different but interrelated functions in motor control. The principal efferent pathway of the primary motor cortex is the corticospinal tract which conducts fine motor control. Damage to the primary motor cortex and the corticospinal tract results in paralysis and loss of skilled, particularly distal, motor function. Lesions of the premotor cortex interfere with the preparation for the execution of movements and coordinating sequences of limb movement. Mediated through cortico-reticulospinal pathways, the premotor cortex adjusts axial and limb muscle activities. The fine motor skills of the corticospinal tract are superimposed upon these stabilizing movements. Supplementary motor area lesions interrupt self-initiated movements, release alien limb behaviors, and result in grasping. Paralysis, primitive reflexes, and frontal gait disorders are readily observed on examination, but difficulties initiating and sequencing movements are more subtle signs of perturbed higher motor control and require special examination procedures. Prefrontal motor syndromes include motor behaviors that only become apparent when the subject performs spontaneous or self-directed activities, unconstrained by instructions from the examiner. Clinical observation also reveals a slowness to respond to instruction with long delays before initiating action (inertia), but once underway they may be unable to stop (perseveration). Patients sit motionless without spontaneous movement or interest in their surrounds (apathy), yet exhibit distractibility, diverting attention to an incidental peripheral stimulus or an object with which they may then fiddle (environmental dependency and utilization behavior). Little spontaneous speech is initiated (abulia) but echolalia may be stimulated by the examiner's conversation. Restlessness, distractibility, perseveration, and environmentally dependent utilization behaviors coexist with apathy, inertia, and abulia. Mutism and akinesia may alternate with stereotypies and agitation in catatonia. These paradoxical combinations are of considerable diagnostic significance in recognizing frontal lobe motor syndromes.
Topics: Humans; Syndrome; Frontotemporal Dementia; Apathy; Motor Cortex; Paralysis
PubMed: 37620084
DOI: 10.1016/B978-0-323-98817-9.00008-9 -
Journal of Neural Transmission (Vienna,... Aug 2015Anhedonia and abulia are syndromes often presented as components of various psychiatric and neurological disorders, including depression, schizophrenia, stroke, multiple... (Review)
Review
Anhedonia and abulia are syndromes often presented as components of various psychiatric and neurological disorders, including depression, schizophrenia, stroke, multiple sclerosis and brain injury. On the basis of the hypothesis that alterations in the dopaminergic motivational system might be involved in the etiopathogenesis of these clinical phenomena, the antidepressant agomelatine is a highly interesting candidate substance for their treatment because of its indirect dopaminergic effects resulting from its melatoninergic and partial anti-serotoninergic properties. Systematic clinical studies are urgently needed to test the hypothesis that agomelatine might be a clinically useful and versatile anti-anhedonic and/or anti-abulic substance.
Topics: Acetamides; Anhedonia; Humans; Hypnotics and Sedatives; Mood Disorders
PubMed: 24311062
DOI: 10.1007/s00702-013-1126-6 -
Practical Neurology Oct 2019The three cardinal qualities necessary for the ideal neurologist are observation, the ability to reason backwards inferentially and specialist knowledge. Modern...
The three cardinal qualities necessary for the ideal neurologist are observation, the ability to reason backwards inferentially and specialist knowledge. Modern medical technology has greatly increased the ability to diagnose and treat disease but it has also encouraged a benign variant of abulia, which is killing off the art and science of clinical reasoning. Intent gazing at the unfamiliar with old eyes or a long look at the familiar with new eyes offers the neurologist an opportunity to discover hitherto unnoticed diagnostic signs far beyond the resolution of the brain scanner and even the light microscope. While there may be nothing new under the sun, there are plenty of old things that no one has observed, which have the potential to greatly improve clinical practice.
Topics: History, 19th Century; Humans; Neurologists; Neurology; Patients; Practice Patterns, Physicians'
PubMed: 30948556
DOI: 10.1136/practneurol-2018-002176 -
Handbook of Clinical Neurology 2019The frontal lobes contain a complex set of diverse anatomic regions that form multiple distinct, complex networks with cortical and subcortical regions. Damage to these... (Review)
Review
The frontal lobes contain a complex set of diverse anatomic regions that form multiple distinct, complex networks with cortical and subcortical regions. Damage to these cortical-subcortical networks can have dramatic behavioral consequences, ranging from apathy to impairments in executive functioning. This chapter provides a brief overview of the common syndromes caused by damage to the mediodorsal and dorsolateral prefrontal circuits, followed by a more detailed review of the syndrome-sometimes referred to as pseudopsychopathy or acquired sociopathy-associated with damage to the ventromedial prefrontal circuit.
Topics: Agnosia; Apathy; Emotions; Executive Function; Frontal Lobe; Frontotemporal Dementia; Humans; Motivation; Nerve Net; Neuropsychological Tests
PubMed: 31590727
DOI: 10.1016/B978-0-12-804281-6.00008-2 -
Neurologic Clinics Feb 2016Frontotemporal dementia (FTD) is a not-uncommon explanation for progressive cognitive deficit in patients who often have a genetic susceptibility for such a... (Review)
Review
Frontotemporal dementia (FTD) is a not-uncommon explanation for progressive cognitive deficit in patients who often have a genetic susceptibility for such a neurodegenerative process. However, FTD does not seem to identify one particular pathogenetic mechanism but rather a spectrum of pathologies with particular predilection for the frontal and temporal lobes of the brain. There have been various subcategorizations of this form of dementia that have a tendency to be of earlier onset than typical Alzheimer disease and heralded by behavioral or communication manifestations. There is a behavioral variant and a language variant, referred to as primary progressive aphasia.
Topics: Aphasia, Primary Progressive; Brain; Frontotemporal Dementia; Humans; Neuropsychological Tests
PubMed: 26613998
DOI: 10.1016/j.ncl.2015.08.007 -
Psychosomatics 2020The pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has emerged as one of the biggest health... (Review)
Review
BACKGROUND
The pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has emerged as one of the biggest health threats of our generation. A significant portion of patients are presenting with delirium and neuropsychiatric sequelae of the disease. Unique examination findings and responses to treatment have been identified.
OBJECTIVE
In this article, we seek to provide pharmacologic and treatment recommendations specific to delirium in patients with COVID-19.
METHODS
We performed a literature search reviewing the neuropsychiatric complications and treatments in prior coronavirus epidemics including Middle Eastern respiratory syndrome and severe acute respiratory syndrome coronaviruses, as well as the emerging literature regarding COVID-19. We also convened a work group of consultation-liaison psychiatrists actively managing patients with COVID-19 in our hospital. Finally, we synthesized these findings to provide preliminary pharmacologic recommendations for treating delirium in these patients.
RESULTS
Delirium is frequently found in patients who test positive for COVID-19, even in the absence of respiratory symptoms. There appears to be a higher rate of agitation, myoclonus, abulia, and alogia. No data are currently available on the treatment of delirium in patients with COVID-19. Extrapolating from general delirium treatment, Middle Eastern respiratory syndrome/severe acute respiratory syndrome case reports, and our experience, preliminary recommendations for pharmacologic management have been assembled.
CONCLUSIONS
COVID-19 is associated with neuropsychiatric symptoms. Low-potency neuroleptics and alpha-2 adrenergic agents may be especially useful in this setting. Further research into the pathophysiology of COVID-19 will be key in developing more targeted treatment guidelines.
Topics: Adrenergic alpha-2 Receptor Agonists; Antipsychotic Agents; Betacoronavirus; Brain Diseases; COVID-19; Central Nervous System Depressants; Coronavirus Infections; Delirium; Dopamine Agonists; GABA Modulators; Humans; Lorazepam; Melatonin; Pandemics; Pneumonia, Viral; Practice Guidelines as Topic; SARS-CoV-2
PubMed: 32828569
DOI: 10.1016/j.psym.2020.05.013 -
Journal of Alzheimer's Disease : JAD 2015Primary progressive aphasia (PPA) is a neurodegenerative disorder characterized by progressive language impairment. The three variants of PPA include the...
BACKGROUND AND OBJECTIVE
Primary progressive aphasia (PPA) is a neurodegenerative disorder characterized by progressive language impairment. The three variants of PPA include the nonfluent/agrammatic, semantic, and logopenic types. The goal of this report is to describe two patients with a loss of speech initiation that was associated with bilateral medial frontal atrophy.
METHODS AND RESULTS
Two patients with progressive speech deficits were evaluated and their examinations revealed a paucity of spontaneous speech; however their naming, repetition, reading, and writing were all normal. The patients had no evidence of agrammatism or apraxia of speech but did have impaired speech fluency. In addition to impaired production of propositional spontaneous speech, these patients had impaired production of automatic speech (e.g., reciting the Lord's Prayer) and singing. Structural brain imaging revealed bilateral medial frontal atrophy in both patients.
CONCLUSION
These patients' language deficits are consistent with a PPA, but they are in the pattern of a dynamic aphasia. Whereas the signs-symptoms of dynamic aphasia have been previously described, to our knowledge these are the first cases associated with predominantly bilateral medial frontal atrophy that impaired both propositional and automatic speech. Thus, this profile may represent a new variant of PPA.
Topics: Aged; Aphasia, Primary Progressive; Atrophy; Female; Frontal Lobe; Humans; Male; Mental Status Schedule; Middle Aged; Speech
PubMed: 25854928
DOI: 10.3233/JAD-142112 -
Behavioural Pharmacology Apr 2023Schizophrenia is a serious neuropsychiatric disorder characterized by the presence of positive symptoms (hallucinations, delusions, and disorganization of thought and... (Review)
Review
Schizophrenia is a serious neuropsychiatric disorder characterized by the presence of positive symptoms (hallucinations, delusions, and disorganization of thought and language), negative symptoms (abulia, alogia, and affective flattening), and cognitive impairment (attention deficit, impaired declarative memory, and deficits in social cognition). Dopaminergic hyperactivity seems to explain the positive symptoms, but it does not completely clarify the appearance of negative and cognitive clinical manifestations. Preclinical data have demonstrated that acute and subchronic treatment with NMDA receptor antagonists such as ketamine (KET) represents a useful model that resembles the schizophrenia symptomatology, including cognitive impairment. This latter has been explained as a hypofunction of NMDA receptors located on the GABA parvalbumin-positive interneurons (near to the cortical pyramidal cells), thus generating an imbalance between the inhibitory and excitatory activity in the corticomesolimbic circuits. The use of behavioral models to explore alterations in different domains of memory is vital to learn more about the neurobiological changes that underlie schizophrenia. Thus, to better understand the neurophysiological mechanisms involved in cognitive impairment related to schizophrenia, the purpose of this review is to analyze the most recent findings regarding the effect of KET administration on these processes.
Topics: Humans; Ketamine; Schizophrenia; Cognitive Dysfunction; Memory Disorders; Receptors, N-Methyl-D-Aspartate
PubMed: 36094064
DOI: 10.1097/FBP.0000000000000689