**1. Introduction**

Diagnosing ataxia in the paediatric age is a challenge since children having difficulty in explaining the symptoms and their temporality and the differential diagnosis can be confusing. Children with ataxia classically present with a difficulty to ambulate often described as a "wide-based gait" [1]. Ataxia is especially incapacitating for children because they are still developing and learning motor abilities [2].

The prevalence of children's ataxia is not widely studied. More reports are focused on single conditions or include adults and paediatric patients. Musselman et al. have estimated the prevalence of ataxia in children is 26/100.000 children [3].

Recognising ataxia is especially difficult in young children, the most frequent reason for consultation is walking instability and loss of balance. History and physical examination represent the basis of the clinical approach [4, 5]. Initially, it is important to determine the temporality of the clinical symptom and elucidate the possible differential diagnosis. Past medical history, including birth history, development, medication, as well a complete family history should be obtained. A history of trauma, medication or toxic ingestion or, recent virus infection should be elicited especially in patients with acute ataxias [5]. In the cases of chronic ataxia, it is important to determine the presence of other neurological symptoms like seizures, sensory abnormalities, or movement disorders.

Physical examination should include skin inspection, looking for telangiectasias, xanthomas or ichthyosis. Neurological assessment must consider the evaluation of the child in a sitting position and during walking. It is important to elucidate if the ataxia is secondary to a cerebellum condition (cerebellar ataxia) or due to other areas of the nervous system (sensory ataxia, vestibular ataxia, etc.) [6]. Abnormal eye movements (abnormalities of saccadic eye movements, nystagmus), dysarthria, dysmetria and dysdiadochokinesis suggest cerebellar ataxia. Paresthesia, impaired position and vibration sense and positive Romberg sign suggest sensory ataxia).

The presence of other neurological signs such as speech disturbances, cognitive impairment, deep tendon reflex abnormalities, or the presence of chorea, dystonia, or myoclonus may be clues to the diagnosis.

Ataxia in children can be in different ways, depending on neuroanatomy (sensory or cerebellar aetiology (primary or secondary), and temporal course [7]. Temporally, ataxia can be divided into two other groups: acute and chronic. Acute ataxias are usually secondary ataxias, whereas chronic ataxia may be either primary or secondary. Chronic ataxias are divided into intermitted or persistent ataxias. Persistent ataxias are divided into progressive and non progressive conditions [6].
