Anesthetic Management in Corpus Callosum Agenesis.

Corpus callosum agenesis develops when the band which connects the two hemispheres of the brain does not occur in utero. It is associated with prenatal infections, genetic factors, toxic exposures, metabolic disorders, and chromosome errors. Mostly seen clinical features are macrocephaly, microcephaly, seizures, motor retardation, hypotonia, eye anomalies, and facial dysmorphisms. Here, we report a case of corpus callosum agenesis syndrome undergoing upper endoscopy under deep sedation with dexmedetomidine. The main anesthetic concerns are difficulty in airway, respiratory problems, gastric reflux, and interaction of the seizures therapy with general anesthetics.

INTRODUCTION

Corpus callosum agenesis is one of the most frequent cerebral malformations with an incidence of 0.5–10 in 10000. Corpus callosum is a white matter structure developed between 12 and 20 weeks of gestation connecting the two sides of the brain. This birth defect can be seen isolated or combined with other cerebral abnormalities such as Arnold–Chiari malformations, Dandy-Walker syndrome, Aicardi syndrome, and Andermann syndrome.[123]

It is important in coordinating information and bilateral exchange of sensory stimuli. Children with agenesis of the corpus callosum may have neurological problems, such as seizures, intellectual impairment, and psychosis. The most common signs were macrocephaly, hydrocephalus, and seizures.[45]

CASE REPORT

A 5-year-old boy weighing 20 kg having the history of seizures, mental, and motor retardation referred to our clinic for upper gastrointestinal endoscopy due to the recurrent respiratory tract infections and gastric reflux. He was the second son of a married couple. His parents were not relative. He was born at full term with cesarean section delivery, weighing 2800 g.

Findings at birth

The weight of the baby at birth was 2800 g with a cranial circumference of 40 cm an Apgar score 6 and 8 at 1 and 5 min, respectively. There was no coiling of the umbilical cord or amniotic fluid turbidity at the time of the birth. Echocardiography showed good heart contractility. No kidney, heart, or immune system abnormalities were found. The metabolic screening tests; serum lactate and ammonium were within normal limits. The color of the baby's hair was blonde, eyes were light blue.

He was drowsy, hypotonic, hyporeflexic with no finger grasp. To investigate the possible dysmorphic syndrome magnetic resonance (MR) was performed. MR imaging of the brain showed macrocephaly with corpus callosum agenesis. He had seizures, myoclonic jerks, macrocephaly, global development delay, and cataract. Neurologic examination revealed a hypotonic infant with the inability to stand unsupported. He was unable to blink his eyes, smile, or frown. Gastroesophageal reflux disease was diagnosed owing to repeated lower respiratory tract infections. He was using long-term multiple antiepileptic drugs and had a cataract in one eye.

The patient was scheduled for upper gastrointestinal endoscopy. Preoperative routine laboratory investigations and hormone profile were normal. After preoperative stabilization and written informed consent from the parents, deep sedation was planned.

In the operating room, the routine monitors were attached and intravenous (IV) access established with a 24 G cannula. Sedation was accomplished with dexmedetomidine IV 0.5 μg/kg/h. He received nasal oxygen breathing spontaneously. Oxygen saturation was maintained between 97% and 100%. Body temperature, heart rate, noninvasive blood pressure, O2 saturation, and end-tidal CO2 were stable during the procedure and postoperative period.

DISCUSSION

Corpus callosum is the largest white matter with 10 million axons. It has a primary role in cognition. Weakened integrity leads to a decline in cognitive function, increased thickness leads to intelligence. Complete or partial agenesis of the corpus callosum includes posterior horns dilatation, nonunion of the calcarine and parieto-occipital sulci. Cranial nerve defects, incomplete separation of the frontal lobes, porencephaly, arhinencephaly, and microcephaly large anterior commissure are the other seen anomalies.[67]

The mechanism leading to the isolated agenesis of the corpus callosum is not known yet. It can be sporadic, an anomaly of the commissural plate, autosomal dominant, or recessive X-linked chromosomal defect. There is no significant difference reported between the sexes.[89]

It may be symptomatic or asymptomatic. Our patient has an isolated and symptomatic form. Epilepsy is found in 50% of patients and generalized seizures are frequently seen. Behavior problems, emotional problems, lack of attention, or hyperactivity are usually detected at the time of schooling.[10] It is diagnosed accidentally sometimes with a wide range of clinical manifestations. It has no unique prognosis. The neonates with ACC are often recognized by the identification of facial or somatic anomalies. The common clinical presentation in children is development delay, seizures, and difficulty learning in school. Agenesis of the corpus callosum can be a part of many chromosomal and mental retardation syndromes.[11] Some syndromes include ACC are Aicardi syndrome, Andermann syndrome, Shapiro syndrome, acrocallosal syndrome optic nerve hypoplasia, Mowat-Wilson syndrome, and Menkes syndrome.[1213]

The main anesthetics concerns are airway difficulties, respiratory problems, gastric reflux, myopathy, cardiovascular disorders, interaction between the polypharma therapy with anesthetic agents. Anxiety should be reduced before the induction, pain also be avoided in the postoperative period. Since the patients have micrognathia, short neck, fiber optic intubation and difficult intubation cart must be ready.[14] In these cases, we see cervical instabilities. Positioning must be performed carefully. Hyperventilation and hypocarbia must be avoided.

In our case, we did not have any airway problems. As shown in Figure 1, we had positional problems due to the contractures and spasticity. The vision problems including cataract did not cause any difficulties for the procedure [Figure 2].

Figure 1

Spasticity, contractures

Figure 2

Cataract in the eye

Chowdhury et al. reported a 16-month-old male child weighing 8 kg with the complaints of intraoral swelling. The patient's MR imaging revealed defect in the base of the skull in the posterior part of anterior cranial fossa and ethmoid region with meningocele sac protruding through the defect in the palate along with corpus callosum agenesis. General anesthesia was performed. The swelling obstructed the laryngeal inlet, Cormack Lehane grade was II. Total duration of the surgery was 8 h. The patient was transferred to intensive care unit under sedation for the anticipated airway edema, he was discharged on the 13th day with full Glasgow Coma Scale score and normal laboratory reports.[15]

Hitosugi et al. stated a high risk of aspiration pneumonia caused by underdeveloped swallowing ability due to callosal agenesis. Attention must be paid for these patients to prevent seizures and aspiration pneumonia.[16]

Kumar reported the safety usage of sevoflurane as an induction and maintenance agent in patients with corpus callosum agenesis syndrome. Trachea was intubated without muscle relaxant with sevoflurane and fentanyl combination in his cases. Kumar highlighted the importance of careful positioning, temperature monitoring, adequate ventilation, preventing aspiration by inserting ryles tube, assessing pain with hemodynamic parameters and parental presence and continuing all antiepileptic drugs in pre- and post-period for the successful management of cases with corpus callosum agenesis.[17]

Dexmedetomidine is a potent alpha-2-adrenoceptor which has sedative, analgesic and anxiolytic effects. In phase III clinical trials, dexmedetomidine 0.2–0.7 μg/kg/h has shown to produce clinically effective sedation and significantly reduces the analgesic requirements of postsurgical ventilated intensive care unit patients. There has not been experienced clinically apparent respiratory depression. Dexmedetomidine produces rapid and stable sedation in patients while maintaining a high degree of patient arousability and anxiety reduction. Dexmedetomidine is associated with a lower rate of postoperative delirium than midazolam or propofol.[18]

In literature review, many anesthetic agents have been used for sedation. For a baby weighing 2600 g with corpus callosum agenesis, a pneumoencephalography was performed under general anesthesia with ketamine. Ketamine 50 mg intramuscular was administered, and rigidity was seen.

In our case, we used dexmedetomidine for both analgesic and sedation effects. Due to its analgesic properties, we did not need to add any analgesic intraoperatively. Dexmedetomidine attenuated the sympathoadrenal stimulation but did not completely abolish the cardiovascular response.

CONCLUSION

Positioning carefully, temperature screening, adequate ventilation, preventing aspiration, and continuing all antiepileptic drugs in pre- and post-operative period can be very helpful in the successful management of corpus callosum agenesis syndrome.

Finally, we concluded that for sedation in children dexmedetomidine is a safe and appropriate anesthetic agent with its better hemodynamic stability effects.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Nil.

Conflicts of interest

There are no conflicts of interest.