Benign Infantile Spasms: This condition is characterized by brief, sudden contractions of one or more muscle groups, often occurring in clusters, and is a common cause of spasms in infants around this age. The age of the child and the nature of the spasms make this a likely initial consideration.

Febrile Seizures: Although more commonly associated with fever, seizures can manifest as spasms in young children. Given the age, any seizure activity, including febrile seizures, should be considered.
Gastroesophageal Reflux Disease (GERD): Infants with GERD can exhibit spasms or arching of the back during episodes of reflux, which might be mistaken for muscular spasms.
Infantile Colic: While typically presenting with crying and fussiness, some infants with colic may exhibit spasmodic movements due to abdominal discomfort.

Meningitis or Encephalitis: Infections of the central nervous system can cause seizures or spasms and are medical emergencies. Early recognition and treatment are crucial to prevent long-term neurological damage or death.
Hyponatremic Seizures: Severe hyponatremia can lead to seizures, which might appear as spasms in infants. This condition requires immediate attention to correct the electrolyte imbalance.
Intussusception: Although more commonly associated with abdominal symptoms, intussusception can cause intermittent, severe abdominal pain that might lead to spasms or posturing in infants.

Tetanus: Although rare in vaccinated populations, tetanus infection can cause severe muscle spasms. The diagnosis should be considered, especially if there's a history of an unhealed wound or incomplete vaccination.
Metabolic Disorders: Certain metabolic disorders, such as pyridoxine-dependent epilepsy, can cause seizures or spasms in infants. These conditions are rare but important to diagnose early for effective management.
KCNQ2-Related Epilepsy: A rare genetic disorder that can cause early-onset epilepsy, including spasms, in infants. Genetic testing may be necessary for diagnosis.