2026 年 11 巻 論文ID: 20260002
Joubert syndrome is a rare autosomal recessive disorder first described by Marie Joubert in 1969. It is characterized by the clinical findings of hypotonia, developmental delay, or intellectual disability. It is also associated with the classical radiological finding known as molar tooth sign on axial magnetic resonance imaging (MRI), which is caused by midline cerebellar vermis hypoplasia, deepened interpeduncular fossa, and thick superior cerebellar peduncles. In addition, Joubert syndrome is often associated with irregular breathing patterns and abnormal eye movements.1,2)
The prevalence of Joubert syndrome is estimated to be 1:100,000.3) Although the neuropathology of this condition has been well studied, rehabilitation strategies are yet to be explored. This case report documents the rehabilitation strategies employed in the management of a child with Joubert syndrome, thereby contributing to existing knowledge and improved outcomes for affected individuals.
An 18-month-old girl was brought to the Physical Medicine and Rehabilitation (PM&R) outpatient department with complaints of difficulty in sitting and delayed speech development. She was the second child born of a second-degree consanguineous marriage, delivered preterm at 8 months via lower-segment cesarean section (LSCS) because of a transverse lie. There was no record of other significant ante-natal or peri-natal history. The mother reported several episodes of breath-holding spells with reduced muscle tone during the first postnatal month. There was no history of seizures. The child attained neck holding at 10 months of age but rolling over was not achieved. Bidextrous grasp was attained by 9 months, unidextrous grasp by 10 months, and crude grasp at 12 months. She was able to pronounce monosyllables at 12 months of age. We observed that she recognized family members and played with siblings. There was no history of any similar illness in siblings.
On examination, the girl’s head circumference was considered appropriate for her age. Facial features included hypertelorism, low-set ears, depressed nasal bridge, and frontal bossing. There was no nystagmus, and no polydactyly or any other skeletal abnormalities were found. Generalized hypotonia was noted. When seated, neck control was fair but showed head lag, with poor sitting balance and trunk control. Voluntary motor control in bilateral upper and lower limbs was fair. Deep tendon reflexes were diminished, and a bilateral extensor plantar response was noted. Primitive reflexes were not observed.
Brain MRI revealed the characteristic molar tooth sign (Fig. 1), bat wing configuration of the fourth ventricle, small dysplastic superior cerebellar vermis, and abnormally thickened bilateral superior cerebellar peduncles. An ultrasound scan of the abdomen and pelvis and a 2D echo ultrasound of the heart with color doppler both showed normal findings. The basic blood profile test was within normal limits (serum 25-OH vitamin D3 level was 13.01 ng/mL). The findings of the ophthalmic examination were normal.
Characteristic molar tooth sign in the brain MRI axial view.
After a detailed examination by a PM&R physician, comprehensive integrated rehabilitation was initiated, including vitamin D supplementation, physical therapy, occupational therapy, speech therapy, orthotics, and psychology services. The management strategies included neurodevelopmental therapy, exercises to improve balance and trunk control, energy conservation techniques, play therapy, and oromotor exercises. A sitting device was prescribed to improve sitting balance (Fig. 2), and bilateral above-knee splints were provided to stabilize the lower limbs and promote standing (Fig. 3). Given the child’s poor antigravity muscle strength and fair trunk control, the orthoses were initially used to facilitate supported standing and were later adapted for gait training. Speech and language therapy was initiated, and feeding techniques were explained to the mother. The parents were given psychological support and counselling. The child received physical and occupational therapy for 45 min per session, five times per week during the first month, and three times per week over the subsequent 2 months. Speech therapy was administered for 1 h per session, twice weekly for the first month, and once weekly for the following 2 months. The parents were also instructed in home-based exercise programs for the child. Regular follow-ups were advised to monitor progress.
Sitting device prescribed for the child subject: a corner seat with chest and pelvic straps for trunk support (upper), and a cut-out table for functional activities (lower).
Bilateral above-knee splints prescribed to support standing and promote stability.
At the 1-year follow-up, at 2.5 years of age, the child had achieved rolling over and showed improved trunk balance. She could sit without support, stand with the aid of objects or a wall, and could walk a few steps using a walker and bilateral above-knee splints. The Gross Motor Function Classification System score improved from level V to level III, reflecting significant gains in gross motor function. The child was able to scribble using a pen, eat with a spoon, and play with toys. Although her speech progress remained limited (she could pronounce bisyllables), she comprehended commands, recognized family members, and identified colors and body parts. The child’s mother reported concerns over the child’s behavior, including easy irritability, restlessness, excessive crying, and marked separation anxiety, which was demonstrated by the child’s refusal to go with anyone other than her mother. The child’s parents provided written informed consent for publication of this report.
Joubert syndrome is a rare autosomal recessive disorder diagnosed through a combination of clinical and imaging features. Classic Joubert syndrome is characterized by the molar tooth sign on axial MRI, intellectual impairment or developmental delay, and hypotonia during infancy. Additional findings include irregular breathing patterns and abnormal eye movements.4) The child described in this report showed all the classic features of Joubert syndrome except for the abnormal eye movements. Joubert syndrome and related disorders (JSRD) is a term coined for the clinical spectrum of diseases, associated with a molar tooth sign on axial MRI when other system involvement is present.5) Different clinical subtypes have been identified based on the involvement of other systems (central nervous, renal, hepatic, ophthalmic, skeletal) and associated findings.6) In a case series by Mano et al.,7) children with JSRD showed gradual motor improvement with rehabilitation and orthotic support, although speech and communication remained significantly delayed; one walked independently by age three, whereas two others did so after 10 years. Similarly, İpek et al.8) reported marked gains in gross motor skills like sitting, crawling, and walking, after 13 months of intensive physiotherapy in a child with Joubert syndrome, despite persistent delays in speech and sphincter control.
Although developmental delay and hypotonia have been classically observed in all reported cases of Joubert syndrome, other noted clinical findings include facial dysmorphic features like broad nasal bridge, low-set ears, trapezoid mouth, frontal bossing, open mouth with protruding tongue; ocular abnormalities like nystagmus, oculomotor apraxia, ptosis, and vertical gaze palsy; and breathing abnormalities like episodic apnea or hyperpnea.4) Cognitive functions of children with Joubert syndrome vary from normal to borderline, whereas intellectual disability ranges from mild to severe in most children. Behavioral issues like inattention, hyperactivity, social withdrawal, and atypical behavior are found in children with Joubert syndrome.9) Autistic behavior has been observed in some children.10) Speech and oromotor findings include expressive and receptive language impairments with lingual apraxia, but signs of oral or pharyngeal dysphagia were not observed.11)
Early identification of symptoms and therapeutic interventions in children with Joubert syndrome may improve clinical outcomes. When a child presents with a history of delayed milestones that may resemble more common conditions like cerebral palsy, an MRI scan of the brain should be recorded to ensure accurate diagnosis and appropriate management. Given that clinical presentation may vary depending on the spectrum of involvement, an individualized treatment plan is recommended. Outcomes in children with Joubert syndrome often vary, necessitating regular monitoring. In addition, the involvement of other systems can make management more complicated.12) As a result, beneficial outcomes are more likely with the use of a tailored rehabilitation plan under the supervision of a physiatrist, allowing the plan to include physical therapy, occupational therapy, and speech therapy along with orthotics as and when required. Therapeutic interventions include neurodevelopmental therapy to help achieve delayed milestones, sensory integration therapy, and speech and language therapy with oromotor exercises. Because the hindbrain is the most commonly affected area in cases of Joubert syndrome, ataxia is a common issue that requires therapy to improve balance and coordination. Play therapy is utilized to improve voluntary motor control in these children. Orthoses (knee-ankle-foot or ankle-foot orthoses) can assist children in physiological standing in the early stages of the condition and can improve gait in later stages. In children lacking sitting balance, the use of a sitting device may provide assistance. For children with behavioral issues, intervention therapies, cognitive behavioral therapy, and parent–child interaction therapy may improve the cognitive functioning and behavior of these children.10)
The study focused on the rehabilitation outcomes of a single child, which limits the generalizability of the findings. Including a larger sample of children demonstrating treatment benefits would provide stronger evidence for the rehabilitation potential in managing Joubert syndrome and addressing the associated challenges. Use of standardized tools like the Bayley or Denver scales, and a structured behavioral evaluation tool, would have provided a more objective evaluation of the child’s progress and rehabilitation outcomes.
Joubert syndrome is a rare neurodevelopmental disorder with characteristic clinical and radiological findings. The condition may also be complicated with other atypical clinical manifestations and the involvement of other body systems. In the present case, early diagnosis through MRI enabled timely initiation of rehabilitation. With supervision from a physiatrist, a multidisciplinary approach used physiotherapy, sitting aids, and orthotic support. This approach led to marked improvements in trunk control and early mobility. These findings underscore the importance of early diagnosis and individualized, team-based rehabilitation in optimizing functional outcomes and improving the quality of life in affected children.
The authors thank the parents of the child subject for permission to publish this report.
The authors declare no conflict of interest.
