A careful history and physical exam are helpful in differentiating between these motor disorders and identifying patients with pure spasticity. First, a detailed history should be taken including birth history, pre- and postnatal complications, and developmental milestones. Children with pure spasticity often have a history of preterm birth, generally around 30 weeks’ gestation, whereas children with other forms of hypertonia tend to have dystonia or a mixed hypertonia.

The physical exam of a child with a hypertonic disorder, like any other, begins with careful and meticulous observation. Spasticity is a hypertonia that worsens with movement and in its pure form is not associated with low tone in the trunk or involuntary movements. Any abnormal posturing, choreoathetoid or writhing movements often seen in the fingers, or a floppy erect torso posture should signal the examiner to consider a mixed disorder of hypertonia rather than pure spasticity.

The physical exam continues with an assessment of upper and lower extremity movements. First, slow passive movement of each extremity is attempted noting the range of motion (goniometric measurement) and any resistance. The limb is then moved rapidly and repetitively while paying careful attention to the loss in range of motion at this higher velocity. Any reduction in the range of motion in the limb’s joints as compared to that seen during slow passive movement indicates that spasticity exists in that limb. In addition to velocity-dependent changes in range of motion, there may also be accompanying increases in muscle tone during rapid movement (manifest by an increase in resistance to passive movement).

Assessment of the pattern of active movement of the limbs during gait is the next key step in a complete physical examination for hypertonia . In younger children, this analysis may be done prior to passive movement of the limbs if the passive examination is expected to upset the child. Typical features to observe during the gait cycle include persistent flexion at the hips, hyperlordosis compensating for hip flexion, and inward rotation at the hip joints with an associated scissoring of the legs. Scissoring can be described as a hyper-adduction of the advancing hip resulting in crossing of that limb in front of the weight-bearing limb. There is often notable spasticity of the hamstring muscle presenting as a difficulty with knee extension and resulting in a crouched stance and shortened stride. Finally, there may also be an equinovalgus deformity at the ankles, where the heels are raised off the ground and oriented outwards throughout the stride. All of these findings (velocity-dependent hypertonia and the above-described gait pattern), in the absence of writhing movements and in the presence of good truncal tone, should offer any provider confidence in suggesting a diagnosis of pure spasticity.

In some patients, however, spasticity of lower limbs may actually be beneficial in regards to weight-bearing ability. For this reason, a complete hypertonia evaluation must assess whether a child is relying on their spasticity to aid in ambulation, and if so, would losing a significant amount of their hypertonicity secondary to a surgical procedure be counterproductive to functional measures. If the child can repeatedly and successfully transition between a squatting and standing position without using their arms or other supports, they are likely to possess adequate underlying muscle strength to maintain the limb’s function in spite of the lost of hypertonia .

When primary care providers see children with spasticity, there are essentially two ways to think about their goals of treatment. Parents can either be guided toward the goal of trying to improve overall motor function or, as is more often the case, toward the goal of reducing spasticity enough to ease the burden of care for daily activities. When deciding upon a successful treatment of patients with pure spasticity, a complete functional assessment should be performed by a physiatrist or physical therapist with specific expertise in these assessments. Relying solely on the physical exam to guide treatment, goals and options would be an injustice to the patient as true functional capabilities are of utmost importance in setting patient, parent, and caretaker expectations for treatment outcomes. While the majority of treatment modalities significantly reduce muscle tone and improve ease of care, they do not directly improve function. It is very important to insure that all those involved (i.e., parents, primary providers, surgeons, physiatrists, and physical therapists) are aware of this while discussing treatment goals and expectations.

The treatment of spasticity is often directed at reducing the burden of care and adequately lowering muscle tone such that daily activities and therapies are more comfortable for the patient and caretaker alike. Routine tasks such as bathing and dressing a child can be severely limited and painful for patients with spastic quadriplegia. Both nonsurgical and surgical treatments aim to decrease the hypertonicity that the caregiver must battle when bathing and dressing the child. In the more highly functioning children with spastic diplegia, the treatment goals may focus more upon obtaining improved function in the legs so as to increase the level of independence for the child within their community. Open and frank communication about the expectations of parents and caretakers and comparing them to the expected functional outcomes after the hypertonia is relieved is of utmost importance in successful treatment. Many parents may have expectations of a fully functional child posttreatment; with these families, discussing realistic outcomes can significantly improve perceptions of success postoperatively.

Treatment modalities for spasticity can be roughly split into two broad categories: nonsurgical and surgical therapies. It is important to understand that for any treatment, the goal is to optimize ease of care and overall functioning. The neurosurgical mandate for managing hypertonicity in these children is to offer intervention to lessen hypertonia if it will improve the likelihood of the physiatrist and physical therapists obtaining meaningful improvement in function. Each method of managing a patient’s hypertonia differs slightly in the type of hypertonia targeted and overall goals of treatment. Therefore a patient’s treatment plan must be developed in a patient-centered manner.