Assignment 2 Lasa 1 Case Studies Presentation By Wednesday N

Assignment 2 Lasa 1 Case Studies Presentationbywednesday November 2

Create a Microsoft PowerPoint presentation to educate a group of medical students participating in their grand rounds. The presentation should include at least ten slides, a title slide, and a references slide. Include speaker notes with main talking points for each slide. Review the two case studies and answer the following questions:

Case Study 1: Isaac, a 59-year-old man, shows signs of Parkinson’s disease, including tremors, muscular stiffness, and slowness of movement. Discuss the symptoms, possible causes (hereditary and environmental), affected brain regions, and why the neurologist prescribed selegiline instead of L-dopa.

Case Study 2: Sabrina, a 27-year-old woman, underwent corpus callosotomy and showed transient apraxia of the left hand. Explain the disorder treated, surgery procedure, expected benefits, risks, and possible alternatives. Clarify the cause of apraxia and what its alleviation indicates about hemispheric specialization.

Paper For Above instruction

This presentation aims to provide comprehensive insights into two distinct neurological conditions through detailed case studies, offering valuable educational content for medical students. The primary focus will be on Parkinson’s disease as exemplified by Isaac's case, and the neurorehabilitative surgery, corpus callosotomy, illustrated by Sabrina’s case. By analyzing these cases, the presentation will elucidate the symptoms, underlying mechanisms, treatments, and neuroanatomical considerations pertinent to each condition.

Introduction

Neuroscience and neuropsychology are crucial domains for understanding brain disorders and their management. Parkinson’s disease is a progressive neurodegenerative disorder affecting movement, while corpus callosotomy is a surgical intervention intended for severe epilepsy that can influence motor and cognitive functions. By exploring these cases, students gain practical insights into disease presentation, diagnostic reasoning, surgical interventions, and the neuroanatomical basis for symptoms and recovery.

Case Study 1: Parkinson’s Disease

Isaac's case begins with subtle symptoms like tremors, which are classical early signs of Parkinson’s disease. As the disease progresses, patients often develop muscular rigidity, bradykinesia (slowness of movement), and postural instability. The tremor in Parkinson's disease is typically a resting tremor, more pronounced when voluntary movement is absent, as was observed in Isaac's scenario. These symptoms predominantly result from degeneration of dopaminergic neurons in the substantia nigra pars compacta, a region within the basal ganglia—specifically affecting motor control pathways.

Both hereditary and environmental factors have been implicated in Parkinson’s disease etiology. Genetic predispositions include mutations in genes such as SNCA, LRRK2, and Parkin, which influence protein aggregation and neuronal survival (Klein & Westenberger, 2012). Environmental factors like exposure to pesticides, rural living, and neurotoxins are associated with increased risk (Van Den Eeden et al., 2003). These factors may promote oxidative stress, mitochondrial dysfunction, and protein misfolding, ultimately leading to neuronal loss.

The affected brain regions in Parkinson’s primarily include the substantia nigra, but also involve the basal ganglia circuitry, including the striatum, globus pallidus, and subthalamic nucleus, which modulate motor activity. The loss of dopamine in the striatum results in impaired regulation of the indirect and direct motor pathways, manifesting as the classic motor symptoms (Obeso et al., 2017).

Regarding medication, L-dopa (levodopa) is the most effective symptomatic treatment because it serves as a precursor to dopamine, helping replenish striatal dopamine levels. However, selegiline, a monoamine oxidase B (MAO-B) inhibitor, was prescribed instead or alongside L-dopa to slow dopamine degradation and reduce motor fluctuations (Olanow et al., 2009). Selegiline's selectivity for MAO-B delays disease progression and prolongs the functional effects of endogenous dopamine, which can be advantageous in early disease stages.

Case Study 2: Corpus Callosotomy and Hemispheric Specialization

Sabrina underwent corpus callosotomy, a surgical procedure involving the severing of the corpus callosum— the major commissural fiber bundle connecting the two cerebral hemispheres. This surgery is typically performed to control severe, refractory epilepsy, especially when seizures involve bilateral spread (Sperling et al., 2014). Post-operatively, patients often exhibit disconnection syndromes, such as an initial apraxia of the left hand, due to interruption of interhemispheric communication.

In Sabrina’s case, the marked apraxia was likely a result of the disconnection between motor planning areas in the dominant hemisphere (usually the left) and the contralateral limb. Over time, this impairment diminished, indicating neural plasticity and compensatory mechanisms. The surgery reduces seizure frequency and severity by preventing the interhemispheric spread of epileptic activity, thus improving quality of life for many patients.

The main benefits of corpus callosotomy include seizure reduction and improved safety by limiting seizure generalization. Risks involve disconnection syndromes, sensory deficits, and, sometimes, cognitive or language impairments. Alternative treatments, such as pharmacotherapy, are less invasive but often less effective in controlling severe epilepsy. If choosing, the surgical option is justified in cases where medication fails, due to its potential to drastically reduce seizure burden (Sperling et al., 2014).

The cause of the transient apraxia after surgery is due to disruption in interhemispheric transfer of motor or sensory information. As neural pathways adapt, other neural networks compensate, leading to decreased symptoms over time. The observed reduction in apraxia highlights the brain’s capacity for neuroplasticity and provides insights into hemispheric specialization, where the left hemisphere generally dominates language and complex motor planning, while the right hemisphere contributes to spatial and certain motor functions (Corballis, 2014).

Conclusion

These case studies illustrate fundamental principles of neuroscience, including neurodegeneration, neuroplasticity, hemispheric specialization, and the rationale behind surgical interventions. Understanding the pathophysiology, clinical presentation, treatment options, and neuroanatomical substrates of these conditions enables future clinicians to develop comprehensive, patient-centered management plans. Continuous research advances our ability to treat neurological disorders effectively, improving patient outcomes and quality of life.

References

• Corballis, M. C. (2014). The Lateralization of Brain Functions. Progress in Brain Research, 213, 13-25.
• Klein, C., & Westenberger, A. (2012). Genetics of Parkinson's Disease. Cold Spring Harbor Perspectives in Medicine, 2(8), a008888.
• Obeso, J. A., Stamelou, M., Goetz, C. G., et al. (2017). Past, Present, and Future of Parkinson's Disease: A Special Lecture. Movement Disorders, 32(4), 680-689.
• Olanow, C. W., Schapira, A. H. V., & Rascol, O. (2009). Continuous Dopaminergic Stimulation in Parkinson's Disease: Scientific Rationale and Clinical Success. European Journal of Neurology, 16(4), 537-549.
• Sperling, A. J., Buckley, S., & Kwan, P. (2014). Surgical Management of Epilepsy: Corpus Callosotomy. Continuum (Minneapolis, Minn.), 20(6 Epilepsy), 1542-1554.
• Van Den Eeden, S. K., Tanner, C. M., Bernstein, A. L., et al. (2003). Incidence of Parkinson’s Disease: Variation by Age, Gender, and Race/Ethnicity. Annals of Neurology, 53(3), 321-328.