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ULY CLINIC

25 Septemba 2025, 05:21:40

Lichtheim’s sign

Lichtheim’s sign is the inability to speak (aphasia) due to subcortical lesions, where the patient cannot verbalize words but can indicate the number of syllables of a desired word using finger gestures. It reflects subcortical language pathway disruption, distinguishing it from cortical aphasia.

Pathophysiology

Normal language processing:
- Speech production involves cortical areas (Broca’s area, Wernicke’s area) and subcortical connections (basal ganglia, thalamus, internal capsule).
Abnormal physiology (subcortical lesion):
- Lesions affecting subcortical fibers connecting language centers result in impaired verbal expression while preserving conceptual and syllabic awareness.
- Patient can signal the intended word’s syllabic structure, demonstrating preserved cognitive-linguistic planning despite motor output failure.

Examination Technique

Patient positioning: Patient should be comfortable and alert, ideally seated.
Verbal assessment: Ask the patient to name common objects or repeat words.
Syllable indication: If speech is absent, ask the patient to use fingers to indicate the number of syllables in the intended word.
Observation: Note consistency between intended syllables and finger signaling.
Documentation: Record presence of subcortical aphasia, syllable signaling accuracy, and associated neurologic deficits.

Clinical Features

Feature	Manifestation
Verbal output	Absent or severely impaired speech
Syllable signaling	Patient indicates number of syllables with fingers
Comprehension	Often preserved, distinguishing from Wernicke aphasia
Associated findings	Contralateral motor or sensory deficits, mild dysarthria, or other subcortical signs
Cognitive awareness	Preserved intention to communicate

Differential Diagnosis

Condition	Key Feature	Notes
Subcortical aphasia	Positive Lichtheim’s sign, preserved comprehension	Lesion in basal ganglia, thalamus, or internal capsule
Broca’s (cortical) aphasia	Non-fluent speech, intact comprehension, cannot indicate syllables	Cortical frontal lobe lesion
Wernicke’s aphasia	Fluent but meaningless speech, poor comprehension	Posterior superior temporal lobe lesion
Global aphasia	Complete loss of comprehension and expression	Extensive cortical involvement
Dysarthria	Impaired articulation but normal language planning	Motor disorder, not aphasia

Special populations

Stroke patients:
- Subcortical strokes (especially left basal ganglia) are classic causes.
Traumatic brain injury:
- May produce similar deficits if subcortical language pathways are affected.
Neurodegenerative disease:
- Rarely, early subcortical dementia can manifest with Lichtheim’s sign.

Limitations

Requires patient cooperation and alertness.
May be difficult to assess in patients with severe motor impairment of the hands.
Rarely observed; must be interpreted in conjunction with imaging and neurologic examination.

Patient Counseling

Explain that the inability to speak is due to damage to subcortical language pathways, not loss of intelligence or comprehension.
Encourage use of alternative communication strategies (gestures, writing, communication boards).
Emphasize early rehabilitation with speech-language therapy to improve functional communication.

Conclusion

Lichtheim’s sign is a clinical indicator of subcortical aphasia, demonstrated by the patient’s inability to speak coupled with preserved ability to indicate word syllables via finger gestures. Recognition of this sign aids localization of subcortical lesions and guides diagnostic and rehabilitative strategies.

References

Lichtheim L. Über Aphasie. Allgemeine Zeitschrift für Psychiatrie. 1885;41:1–70.
Kertesz A. Western Aphasia Battery–Revised. San Antonio, TX: Pearson; 2007.
Damasio AR. Aphasia. N Engl J Med. 1992;326:531–539.
Ropper AH, Samuels MA, Klein JP. Adams and Victor’s Principles of Neurology. 11th ed. New York, NY: McGraw-Hill; 2021.