What Is Corpus Callosotomy?
Corpus callosotomy (CC) is a surgical procedure that is used to treat epilepsy. Epilepsy is a chronic condition marked by recurring seizures. The corpus callosum is a bundle of nerve fibers that helps the brain's hemispheres communicate with one another and is severed by the neurosurgeon during this treatment. The procedure tries to reduce epilepsy (a disorder of the brain that causes seizures) symptoms by interfering with the hemispheres' ability to transmit seizure signals. This procedure, also known as split-brain surgery or callosal sectioning, lessens the effects of seizures ( unregulated electrical activity of the brain) in both adults and children. Though it does not completely stop seizures, it can lessen their frequency and intensity, providing a possible course of treatment for people with refractory epilepsy.
What Are the Indications of CC?
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When a person with epilepsy still experiences seizures after taking a variety of anti-seizure drugs, surgery may be an option. For seizures referred to as drop attacks (abrupt falls, with or without unconsciousness, caused by abnormal leg muscular contractions or a breakdown of postural muscle tone), a particular procedure known as a corpus callosotomy (CC) is beneficial.
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Seizures of different kinds, such as atonic (sudden loss of strength and tone in the muscles), tonic (the legs, arms, or trunk muscles suddenly stiffen or tense), spasms (involuntary, forceful contraction of a muscle that prevents it from relaxing results), and myoclonic (sudden, uncontrolled muscular spasms), are included in these episodes. Occasionally, the person may fall and injure their forehead or face. Depending on how severe their seizures are, CC may be an option even for immobile individuals who do not have drop attacks.
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Other seizure types can also benefit from this surgery. Before prescribing CC, doctors frequently search for particular patterns in the brain's electrical activity, such as synchronized or independent spikes.
What Are the Treatment Options and Success Rates for Children Undergoing Corpus Callosotomy to Manage Seizures?
Children who get corpus callosotomy see a significant decrease in seizure frequency and intensity in 80 percent of the cases. The child's physician will offer information about the procedure's likelihood of success specific to the child. Although there is always the option to keep taking medication to control seizures, the effectiveness of these treatments tends to wane with each new medication trial, providing little opportunity for sustained seizure control. The medical team will consult with the parents or caregivers to examine the appropriateness of alternative treatments, such as the ketogenic diet or vagus nerve stimulation (VNS) therapy.
How Is CC Performed?
General anesthesia is used during a corpus callosotomy to guarantee the patient's unconsciousness. A craniotomy (the brain is exposed after removing the skull) is started by the neurosurgeon by excising a section of the skull and carefully removing the dura, which is the outer membrane that surrounds the brain. The corpus callosum is then meticulously sliced using specialist instruments under surgical microscopes. The dura (outer layer of the skull) is then restored, and staples or stitches are used to reposition the skull bone. In some instances, the process is done in two steps. The first step involves the front portion of the corpus callosum, which permits the brain's various regions to continue exchanging visual information. A second procedure to sever the corpus callosum may be considered if the patient continues to experience severe, ongoing seizures.
What Are the Surgical Compilations of CC?
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Hydrocephalus and Subdural Fluid Collection - Subdural fluid accumulation (cerebrospinal fluid collection between the outer lining of the brain, also known as the dura mater, and the brain’s surface) may happen following CC, particularly in events of brain shrinkage. Usually, there are no symptoms associated with this. However, when the lateral ventricle opens during the callosal section, it may result in hydrocephalus, a neurological condition caused by an abnormal accumulation of cerebrospinal fluid in the brain's deep ventricles or cavities. The ventricles expand due to this extra fluid, damaging the brain's tissue. To minimize the possibility of hydrocephalus and fluid accumulation, surgeons attempt to prevent opening the lateral ventricle. If it happens accidentally, they can cover the opening area and help avoid difficulties using a special sponge saturated in adhesive.
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Hemorrhage and Infarction - One possible cause of subdural hematoma is injury to the bridge veins that connect the superior sagittal sinus (midline vein) to the brain surface. Excessive brain retraction can result in intraparenchymal hemorrhaging (bleeding in the parenchyma of the brain). Damage to the pericallosal or callosomarginal arteries (both branches of the anterior cerebral artery) may cause an infarction (tissue death due to decreased blood supply) in the anterior cerebral artery's area. To prevent injury to bridging veins, brain parenchyma, and arteries, performing gentle brain retraction is crucial, replacing the spatula multiple times and covering arteries with rayon patties during all microsurgical procedures.
How Is the Recovery and Rehabilitation Process Post-surgery?
Depending on their pre-surgery neurologic state, each person recovers from a corpus callosotomy differently. A return to routine activities is expected within six to eight weeks of hospitalization, which usually lasts several days. However, recovery times vary depending on possible adverse effects and the depth of the callosotomy. After surgery, patients are expected to continue using antiseizure drugs even when the operation does not eliminate seizures. Short-term consequences of surgery could include sadness, exhaustion, headaches, memory problems, nausea, numbness where the incision was made, and trouble speaking. Any alarming symptoms, such as increasing or severe seizures, chronic headaches or nausea, or evidence of an infection, such as slurred speech or sudden paralysis on one side, should be reported to the healthcare professional at once.
What Are the Key Considerations in Addressing Disconnection Syndrome and Selecting Corpus Callosotomy Approaches for Seizure Control?
Disconnection syndrome, classified as acute or chronic, is the main reason for concern following CC. Patients with acute cases have major reductions in spontaneous speech, nondominant limb paresis (weakening), and incontinence. The severity varies; some may need to be fed through a tube or receive the nutrition intravenously because of a substantial reduction in activity.
Aspiration pneumonia (lung infection triggered by oral content aspiration) can also be caused by severe dysphagia (difficulty swallowing). Over several weeks to months, these symptoms usually become better. Alien hand syndrome, dichotic listening suppression, tactile dysnomia, hemispatial neglect, nondominant hand agraphia, and tachistoscopic visual suppression are among the symptoms that people with chronic disconnection syndrome may suffer. Varying degrees of severity, especially in older people, may result in impairment.
Regarding seizure outcomes, total corpus callosotomy (tCC) has proven superior to anterior two-thirds callosotomy (aCC). But to reduce the danger of disconnection syndrome, aCC is recommended for older patients as it protects the corpus callosum's splenium. Standardized standards for selecting aCC over tCC are still pending. Patients over 15 are eligible for aCC, while patients under 10 are only eligible for tCC. The degree of CC is assessed in patients between the ages of ten and 15 using information from their electroencephalogram, everyday activities, and cognitive abilities. Additional posterior one-third callosotomy (pCC), usually performed at least three months after aCC, is suggested if seizure control is still insufficient.
Conclusion
To perform a corpus callosotomy (CC), basic neurosurgical methods must be used. Preserving a low incidence of problems is essential to CC's acceptability as a surgical option for epilepsy that reduces seizures. Prioritizing careful surgical procedures and strategies to reduce the complication rate is imperative for surgeons doing this treatment. The doctors treat every case differently for the best outcome of the surgery.
